Answer:
Some people wait until they're older to lose their virginity because every person you have sex with is kind of with you forever. You'll always remember your first, and so will your partner. Imagine that you have a boy friend who has already done it with some other girl. How would you feel? It bothers some people. It's not evil, but it's a very special thing.
If you don't have sex, you don't have to worry about pregnancy, or AIDS, or STIs.