How to Forget a Bad Memory
To push a bad memory out of your head, try to avoid places or situations which remind you of an unpleasant time in your life. If you can't avoid triggering the memory, try reframing how you think of it. For instance, if you can't stop thinking of a time someone hurt you, try reminding yourself how strong you felt the next time you stood up for yourself. Then, practice switching to a happier memory every time the bad memory comes up.
Avoid objects and places that trigger the memory. Do you notice yourself getting blindsided by your bad memory when you go certain places or are around certain things? Maybe you haven't realized that they're what's triggering your memories. For example, maybe your bad memory is related to an incident that happened at your elementary school, and you recall what happened every time you pass it. If you start taking a new route to work in the morning and avoid the street where your school is, you can keep your mind bad-memory-free a bit more often. If you're able to completely avoid the things that trigger your bad memory, it might eventually fade out of your mind. You'll have fewer reasons call it up, and as you keep living life you'll replace the bad memory with more important thoughts. Of course, not all triggers are entirely avoidable, and maybe you don't want to have to change your route to work, or donate your collection of science fiction books, or stop listening to your favorite band just because the last time you saw them live was the night your ex told you he was ending the relationship. If avoiding triggers isn't feasible, either because there are too many of them or you resent giving the memory that power, there are other ways you can deal with the memory. Think about the memory until it loses its power. This step works for many people. The first few times you remember something bad, it might catch you off guard and leave you feeling anxious and deflated. Your impulse might be to avoid thinking about it as much as possible, but trying to suppress the memory can give it more power when it does pop back up in your mind. Instead of pushing it out of your mind, let yourself remember what happened. Keep thinking about it until it loses its sting. Eventually, you'll just stop thinking about it so much, and when you do, it won't be painful anymore. If the memories become heavier on your mind then get on a long walk or do any exercise briskly. Try to take comfort in the fact that the event causing the memory is over now. Whatever happened - people laughing at your embarrassment, or a dangerous situation you endured - is in the past. In some cases, thinking about a bad memory can become a little obsessive. Observe your emotions as you repeatedly recall the memory. If you realize that even after deliberately thinking about the memory it still has the power to hurt you, then try a different method for getting rid of the bad memory. Try memory alteration. Every time you remember something, the memory changes a little bit. Your brain makes up for tiny gaps in your memory by replacing them with false information. You can take advantage of the way your brain works by replacing the bad parts of a memory with different information. Eventually, you'll start recalling the changed version. For example, let's say you have a childhood memory about riding in a boat called "The Dreamcatcher" on a lake with your dad. You remember your dad at the stern wearing red shorts and sunglasses, shouting as he watches you lean too far over the rail and fall into the water. You know this is what happened, but years later when you look at a photograph from the day you see your dad was wearing jeans, and the boat was called "The Kingfisher." As you see, memories are never completely accurate, and they can be changed. Try altering the part of the memory that makes you feel bad. Using the above example, if you remember feeling scared and alone when you fell into the lake, try re-imagining the memory so that you focus on how great it felt to get rescued by your dad. Every time you think about the memory, it will be a little different. If you focus on the good feelings instead of the bad each time, the memory will begin to change in tone. Maybe it won't go from being a bad memory to a great one, but it might lose the power to hurt you. Focus on happier memories. Sometimes our brains get into ruts that are difficult to climb out of. If you find yourself dwelling on bad memories a lot, train your mind to switch to happy memories instead. Don't give a bad memory enough time to change your mood or make you feel anxious; instead, the moment it comes into your mind, shift your thinking to a happier memory. Keep practicing positive thinking until you no longer automatically fall into the same old mental ruts. Try pairing your bad memory with a good one. For example, if you can't stop thinking about a time you fumbled a presentation and the whole class laughed, pair that memory with the memory of a time you performed well and received praise. Each time you think about the bad memory, shift your thoughts to the good one. Having a good memory fresh on your mind will keep you from having to rack your brain for something positive to think about when you're feeling bad. Learn to be in the present. The practice of paying more attention to the present moment is called being mindful. It means focusing on the here and now instead of dwelling on the past or nervously anticipating the future. Being mindful is an excellent way to relieve stress and get more out of life. Instead of spending time and energy worrying about things you can't change, you get to let go of baggage and just be. Oftentimes, people let their minds drift off during their daily activities, and they completely tune out what they are doing. Instead of going on "autopilot," take the time to notice small details, like sounds or smells that you wouldn't normally pay attention to. This will help bring your mind back to the present moment rather than drifting off and fixating on memories. Adopt a mantra you can repeat when your thoughts drift to places you don't want them to go. For example, you could say "I am here" or "I am alive." Say something that grounds you in the present. This will help you to realize that you have a choice. Pay attention to how your body feels right here, right now. Pay attention to your senses: what do you hear, see, taste and smell right now? Make sure that you do not limit your senses to memories of the past. Try meditation. Most forms of meditation are all about mindfulness. Focusing on breathing and freeing your mind from distractions helps you live more fully in the present. Regular meditation practice not only helps you focus, it has also been shown to improve overall mood. Consider what you learned from the event. Even the most horrible experiences can teach us something. It might take you a long time to realize what you have learned, especially if the incident is fresh. But if you can look back and see that you gained wisdom from the situation, your bad memory might lose some of its sting. Can you find a silver lining you haven't noticed before? Remember that negative experiences are an inevitable part of life. Difficult experiences make us stronger, and help us appreciate the pleasurable moments in life. Without feeling bad once in a while, we wouldn't be able to appreciate feeling good. Try to count your blessings. Whatever you may have lost as a result of this memory, make a list of the things that you are thankful for now. Form happy new memories. As time passes, the bad memory will naturally start to fade a little. You can speed up the process by living life fully and creating new good memories to fill your mind. Spend time doing things you enjoy with people who make you happy. The more positive memories you make, the less significant the negative ones will seem in the long run. It can help to go to places you've never been before, so you can have brand new experiences that aren't tainted by the past in any way. Book a flight to a new city, or be a tourist in your own city and go to a neighborhood you don't usually frequent. If traveling isn't your thing, change up your routine in some other way. Go to a new restaurant you've never tried, cook a challenging meal, or invite all your friends over for a dinner party. Have a busy life. Keep your schedule full and your mind stimulated, so you have less time to dwell on negative thoughts. If you tend to spend a lot of time by yourself, make it a point to go out more with friends, or visit your family more often. Distract yourself with a good book, or pick up a new hobby. The more time you spend sitting around with nothing to do, the more likely you are to dwell on old memories. Here are a few great distractions that will help you stay busy: Take up a new physical activity, like soccer or kickboxing. If you're not into sports, challenge yourself to walk a certain number of miles each day, or start doing yoga. Challenging yourself physically is a great way to free your mind from negative thoughts. Exercising causes your brain to release endorphins that improve your mood. Create something new. You could sew a dress , make a painting , or write a song. Pour your energy into making something, and you won't have time to think about bad memories. Find an opportunity to volunteer your time. Helping other people is a great way to get your mind off of your own troubles. Avoid alcohol and drugs. Using mind-altering substances can make things worse, especially if the bad memory has left you feeling depressed or anxious. Alcohol can increase depression, irritability, and anxiety, especially in people who have already been experiencing these symptoms. To keep your mentality positive, it's best to limit or completely abstain from using alcohol and drugs. Using alcohol and drugs as a way to try to forget bad memories, or as a way to avoid any type of negative emotion, often leads to addiction. If you find yourself turning to alcohol or drugs when you don't want to have to remember something that bothers you, seek help now. Other forms of escapism should also be avoided. If you tend to gamble, overeat, or take refuge in a habit that could be detrimental to your health as a way to suppress bad feelings, it's important to acknowledge your behavior and curb it, either on your own or with the help of a therapist or support group. Make your health a priority. When you're consumed with negative thoughts, it can be tough to remember to take good care of yourself. But keeping your body in good health has a big effect on the way you think. Eating nutritious food, getting plenty of sleep, and working out a few times a week will go a long way toward keeping bad memories at bay. In addition to making sure your basic needs are met, take time to pamper yourself a bit to help ease the anxiety stemming from your bad memory. Eat a balanced diet that includes plenty of fresh fruit and vegetables, lean protein, whole grains and healthy fats. Aim to get 30 minutes to an hour of exercise every day, even if you just take a long walk after work. Try to get seven to eight hours of sleep every night, since being fatigued can make your emotions run higher than usual and leave you susceptible to dwelling on bad memories. Grieve the memory. Acknowledge the memory and the negative emotions associated with it. While this may seem counterproductive, catharsis is a key element of the healing process. Suppressing a bad memory will only cause it to come up again later in life, and with even more intensity. Let yourself feel angry, sad, embarrassed, or hurt. If you need to cry or scream, do it. You'll come out on the other side feeling more able to cope than if you tried to ignore your pain. Talk to somebody about it. Turn to a friend or family member whom you trust. Other people can offer advice, share similar stories, and even reassure you that perhaps the incident wasn't as horrible as you have made it out to be in your head. If possible, talk to someone who is unrelated to the incident; this will give you the fresh perspective that you need. Consider joining a support group. Do some research to find a support group in your area that deals with the particular issue at hand. There are many support groups out there for recent divorces, breakups, chronic illnesses, and so on. If you are not comfortable sharing the experience with anybody else, write about it in a personal journal and keep it in a safe place where nobody else will find it. Consider getting psychotherapy. If you feel you need more than a friend or family member can offer, talking to a professional might be the right choice for you. Since the doctor-patient relationship is confidential, you don't have to worry about censoring yourself or feeling embarrassed.  A therapist will be able to help you identify your triggers and learn to overcome them. He or she will teach you techniques you can use to break the hold bad memories have on your mind. Cognitive behavioral therapy has been found to be helpful for people dealing with trauma. Consider seeking out a therapist that specializes in this approach. Find out if you have post-traumatic stress disorder (PTSD). This disorder can develop after a terrifying and harmful experience, such as being sexually abused, getting in a bad car accident, being violently assaulted, or having a debilitating illness. For people with PTSD, memories of trauma don't fade away. It produces a feeling of constant anxiety that the bad situation will happen again. If you think you might have PTSD, it's important to seek help, since it's not something you can deal with by yourself. Symptoms of PTSD include having flashbacks, nightmares, and thoughts that frighten you. You may feel emotionally numb, depressed, or constantly worried, with a feeling of being on edge all the time. Look into special treatments. If you feel trapped by your memories of a traumatic experience, there are treatments available that may help. These treatments are usually used in conjunction with psychotherapy for the best possible results. Make an appointment with a psychiatrist to discuss whether a special treatment might help you finally feel free of the bad memories that are affecting your quality of life. Medication might be the first treatment to try. Antidepressants or anti-anxiety medication is often prescribed to people who have difficulty escaping negative thoughts. Somatic experiencing is a treatment aimed toward getting you back in touch with what your body is feeling. It focuses on correcting the fight-or-flight response so that it no longer becomes activated when danger isn't present. Electroshock therapy is an effective way to relieve the mind of traumatic memories when no other treatment works. 
Avoid objects and places that trigger the memory. Think about the memory until it loses its power. Try memory alteration. Focus on happier memories. Learn to be in the present. Consider what you learned from the event. Form happy new memories. Have a busy life. Avoid alcohol and drugs. Make your health a priority. Grieve the memory. Talk to somebody about it. Consider getting psychotherapy. Find out if you have post-traumatic stress disorder (PTSD). Look into special treatments. 