Task: Assess the emotional content of the tweet and classify it as either 'neutral or no emotion' or as one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best represent the tweeter's mental state.
Tweet: @TweeriaLee A stumbling block to the pessimist is a stepping stone to the optimist.
This tweet contains emotions: 
optimism