Did you ever lend a large a large sum of money to another person who is yet to pay you back?

It wasn't a HUGE sum, but it seemed quite large to me at the time. $500.00. I loaned it to a co-worker, and I even made her sign an agreement that she would pay it back, because it was my tax money that I had saved.

Turns out she was a deadbeat, and NEVER paid me back.