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: Why is it that we rejoice at a birth and grieve at a funeral? It is because we are not the person involved. ― Mark Twain
This tweet contains emotions: 
optimism