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