Riddle: When I am young, I am tall. However, when I am old, I am short. What/Who am I?
Answer: A candle. When a candle is freshly lit, it is still tall, but when the candle has been used for a while, the wax melts and the candle gets smaller.
Riddle: A janitor is in a closet. The janitor jumps out of the closet. There are many other people waiting for the janitor. What do the people say when the janitor comes out?