Task: Assess the emotional content of the tweet and classify it as either 'neutral or no emotion' or as one or more of the given emotions (anger, anticipation, disgust, fear, joy, love, optimism, pessimism, sadness, surprise, trust) that best represent the tweeter's mental state.
Tweet: This tweet is dedicated to my back pain, which I do not understand because I am youthful and spry. Full of life. Vivacious.
This tweet contains emotions: 
joy, optimism, sadness