Task: Classify the mental state of the tweeter based on the tweet, determining if it is 'neutral or no emotion' or characterized by any of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: I've learned to let go of resentment for people who have hurt me, because keeping it is like swallowing poison and expecting them to die.
This tweet contains emotions: 
anger, optimism