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: Difficulties, by bracing the mind to overcome them, assist cheerfulness, as exercise assists digestion.\nChristian Nestell Bovee #quotes
This tweet contains emotions: 
joy, optimism