I shouldn't laugh, I really shouldn't.
Poor old OopsCat, he's 17, blind, arthritic and has hyperthyroidism. Due to the arthritis, he can't quite reach that bit of him that's behind his shoulder - you know, when a cat twists their head right round to nibble at? Well, he can't get at it with his teeth, and he can't get at it with his back leg, so he does this amazing twisted-up epileptic pretzel imitation when he gets an itch there - his head is on backwards and his back leg is scratching frantically (but nowhere near where it needs to be).
Today he got that itch. While he was peacefully snoozing halfway up the stairs. Cue frantic pretzel imitation... and five seconds (and a lot of thump-thump-scrabble-thump) later he's at the bottom of the stairs looking very confused. And washing his bum, because that's what he does when he's embarrassed. 
Poor cat. I almost feel sorry for pissing myself laughing at him. 