We've only lost one once, it fell off of a backpack when it got snagged somewhere in line. We didn't even realize it until the end of a 2 week trip, because it was one of the 'extras' we had for playing Sorcerers of the Magic Kingdom once upon a time and we just collect them on our backpacks....
Lo and behold it was sent to us and had been waiting in our box when we got there about a month later!
This also happened to us when we went for our wedding 20 years ago and our guests had those disposable cameras!! Someone had misplaced it, but we didn't even realize it, just figured one of our guests took it home!! We got home after a long honeymoon and there it was in our mailbox with a few cast member photos congratulating us!! HAAHA!! They were specialty wedding ones with a label of our wedding info on it (we were married in WDW) and they tracked us down that way!!
Disney Magic never ceases to amaze me and we have so many stories, so never lose out hope!!!