Task: Determine the dominant emotion in the tweet and classify it as either 'neutral or no emotion' or one of the eleven provided emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust).
Tweet: Regret for the things we did can be tempered by time; it is regret for the things we did not do that is inconsolable.  Sydney J. Harris
This tweet contains emotions: 
optimism, sadness