Task: Categorize the tweet's emotional expression, classifying it as either 'neutral or no emotion' or as one or more of the specified emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that reflect the tweeter's state of mind.
Tweet: we never taste happiness in perfection, our most fortunate successes are mixed with sadness. #success #sadness #perfection #fortunate #mixed
This tweet contains emotions: 
optimism, sadness