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: 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