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: Let us not burden our remembrances with a heaviness that's gone.\n- William Shakespeare (1564-1616)\n#forge ahead.
This tweet contains emotions: 
optimism, sadness