Task: Determine the prevailing emotional tone of the tweet, categorizing 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 most accurately represent the tweeter's mental state.
Tweet: Today's realisation that it was the last time I watch swimming lesson cos I go back to work next week lead to a joyous bedtime. #worstoneyet
This tweet contains emotions: 
anticipation, disgust, joy, optimism, sadness