Task: Identify the primary emotion conveyed in the tweet and assign it to either 'neutral or no emotion' or one or more of the provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best capture 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