Life is a dream. Life is a journey to nowhere. Life is a series of unexpected and expected experiences. Life is a cartoon. Life is what you make of it.
Life is a journey whose destination is unknown.
Life is a treasure and the proof of that is that few people want to die. Life is hard but beautiful, too. Life is a very high mountain. Life is a film in which you are the main character. You could even devote a whole class to discussing student comments.