I used to be really cool with letting people borrow things. I would sometimes get nice stuff, and I wanted people to talk to about how cool game XYZ was so hey why not?
Of course it seems like most people don't give a shit about returning things or making sure they don't dirty up your stuff.
In elementary and middle school I had people "lose" things I let them borrow all the time. An entire two plastic sheets of holographic/rare Pokemon cards mysteriously vanished from my backpack. Once this POS dude who was a bully came and rang my doorbell and asked for Spyro 2. I was really scared of him so I handed it over, and as he walked away I just thought "I'm never seeing you again, goodbye old friend, we had some fun together." A really nice shiny red cd player that was apparently taken up by a teacher but the teacher had no idea what I was on about when I asked. I eventually started saying no to requests to borrow things, and of course when you do that everyone thinks you're an asshole. v(0_0)v
Once in high school I let a "friend" borrow Stella Deus. I didn't really like this game at all, but I had paid basically full MSRP for it, so I wanted it back. I pestered him for a while and eventually he said " Let me borrow Tales of Legendia and I'll bring it back."
WOW, the nerve. I basically turned around and walked off, never spoke to him again.
I'm also pretty sure one (or both) of my nephews decided to walk away with my copy of Kingdom Hearts and a memory card. They were always playing it any time they were over, and once while alphabetically sorting my games I noticed it was gone. I don't mind the game so much (more incentive to get the HD remixes) but the memory card really hurt. Had save files for tons of RPGs on there, .hack//GU 1 and 2 clear data, etc. Since they go over to their dad's house I don't expect to ever see it, due to family drama. Basically they're not allowed in my room unsupervised now.
There is only one person who has ever returned a game I let him borrow ASAP, when I asked for it. He has my confidence for life, this happened in middle school and I didn't meet him again until college, and I still felt safe letting him borrow stuff.
During the move, I had to leave a chunk of our personal belongings. Simply not enough room in the van for everything. So I arranged to have a friend keep it in his place until I could make the return trip to pick it all up. Among the things left were my entire NES, Genesis, Sega CD, and Jaguar collections.
Of course it didn't take long for this friend to reveal his true stripes and claim that since I wasn't there anymore, he was taking ownership of everything. I'm in the process of trying to replace the collections, but it isn't cheap and it's been piecemeal at best. Still fewer have any materials like boxes or maps/manuals. I had complete boxed copies of stuff like all six Mega Man games, all four Dragon Warrior games, all three TMNTs, all three Ninja Gaidens, all three Castlevanias, Contra and Super C, the original Final Fantasy, both Lunar games on Sega CD, both Mutant Leagues, Warriors of the Eternal Sun, Gunstar Heroes, Castlevania Bloodlines, Contra Hard Corps, and many others. Some 100+ games total. Just thinking about it fills me with rage.
Whhhhaaaaat. A whole collection, I would have seen if the cops would go talk to him (even if they can't really "do anything") just to make his life a little harder.
Some people are just scum. :/