Just like the phrase "You are what you eat", meaning what you consume literally makes up every cell in your body, the same can be said for your mental space: You are what you think.  If you are not watching what the mind thinks, you are mindlessly thinking and in turn, effectively internalizing everything that crosses your mind; and in that regard, you are literally mindless as you, the awareness reading these words has developed the habit of completely identifying with every thought.

Too often I find myself putting food into my mouth for no reason and way too quickly/repetitively. when I happen to for one reason or another, break free from that state of mindless eating, I become more aware of it and by simply acknowledging its existence, can mindfully decide what food I want to consume or put down and how much of it.

From my understanding, the same can be said for our mental state. Bringing awareness to your thoughts effectively provides necessary distance between what you are thinking and what you are internalizing. 

If you often find yourself judging, worrying about the future, and lamenting the past, then unless you acknowledge those thoughts and as a consequence become more aware of how irrational/fruitless they can be, you are at their mercy and incorporating them into the scaffolding of your mental state for the foreseeable future. 

Freedom from identifying with every thought that crosses your mind is a matter of bringing awareness to every thought that crosses your mind. if you arent aware of the thoughts, you are automatically internalizing 100% of them, both good and bad.

"You are not usually conscious of all your thought patterns, the only way to bring them into your awareness is by watching your emotions" - Eckhart Tolle