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: Haven't yet read why Dutch drivers are so happy, but here's my theory: because they could quit driving and still have great transpo options.
This tweet contains emotions: 
joy, optimism