As I rode home on the bus yestereday a young lady sitting next to me noticed me typing on my laptop, and asked me a question about, of all things, backups! She worked in a medical facility, and wondered why their backups took longer by the end of the week than the beginning. You can probably guess the answer to that one - her company is probably using some kind of "differential" backup. While she didn't know anything about that, I did ask her if she had ever been asked to test one of those backups by restoring it somewhere. She said no.
Don't be that lady. Find a box somewhere today and check your restore procedures. You should have a regular schedule to do that.