I know, it's outrageous that I was willing to hand that much over to him, and it's outrageous that he has convinced himself he doesn't need to pay it back, even though he always said he would.
It has occurred to me to take him to small claims court, but I don't even have an address for him--I don't even know what country he's in at the moment. And anyway, as you all are saying, outrageous as it is, maybe it would be better just to let it go so that I can have some peace.