There is an old thread entitled "Weirdest disc find ever..." - I suggest looking it up for some interesting stories on lost discs being found/returned.
Here is a classic from a friend of mind (yeah I'll claim BA as a friend)
Last year I lost my favorite go-to disc on the river hole at Arlington. As soon as it left my hand I thought "Why the f-ck did I just throw that disc?". It was the day before a tournament being held there too. The hole was a big anheizer hole and I left the "an" in my bag. It went 50 feet out, turned left and landed about 100 feet out in the middle of the raging Stillaguamish River (during flood season). I used that disc on at least half the holes out there. I was bummed, and I sucked during the tournament (but had fun)
About 6 months later I get a call from some crazy woman saying she found my disc near Arlington and would trade me for a case of beer. She described the disc and sure enough, it was the river disc. I told her it was only worth a 6 pack new, and she said if I just swung by her house she would give it to me for free.
So a buddy and I (I needed a friend because she sounded a little nuts) grabbed a 12 pack of Bud and drove over to her house. Her whole neighborhood (in a pretty scary part of Everett ) were waiting to see if we would really show up.
The day before, this woman and about 4 of her neighbors went rafting down the Stilly. One of the guys had to piss, so they pulled the raft over directly under the I-5 bridge. One guy hiked away to pee and looked down while relieving himself and saw something orange sticking out of the sand. It was my disc. They joked about it and said they bet they could trade it for some more beer.
We ended up drinking the beer with her and her neighbors, , taught them what disc golf was about, and made some new friends that day.
That disc traveled about 6 miles downstream, buried itself in the sand, got pissed on, and found its way back to my bag.
It never flew correcty again, but I still love it just the same....