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: 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