What have you accidentally trained your pet to do?

I "trained" my cat to open doors by jumping on the door handle (we don't have those chunky round turn knobs in Germany). I don't know how, he just observed and put 2 and 2 together, I guess ( apparently he was a math wiz, too, har har).
So, I had to lock all my doors to prevent him to get into certain rooms, or even outside.
Unfortunately, that didn't stop him from trying, so I would constantly wake up to the ka-chunk of the door handle flipping up after the unsuccessfully tried to pull it open.
He won, and I just left all doors open at all times.

So, really, it wasn't me accidentally training him, it was he who intentionally trained me!

/r/AskReddit Thread