Task: Categorize the tweet's emotional tone as either 'neutral or no emotion' or identify the presence of one or more of the given 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