Good Riddles

Question: Three men rob a store but come out completely changed. Yet they continue robbing other stores.

What kind of store did they first rob?

Question: Why don't most buildings have a 13th floor?

Question: What's always coming, but never arrives?

Question: I'm heavy but not backwards.

What am I?

Question: What does a man do only once in his lifetime, but women do once a year after they are 29?