I've never gone off and left the stove on but I do do something very stupid.
We got a new stove a couple of years ago (and yes, I still do this stupid thing even though it's been a couple of years ) and the knobs for the front and back are different than they were on my old stove.
Well, I have covers on the burners and I always seem to turn on the front one when what I really want is the back one. I bet I've done this at least 10+ times Luckily I'm always standing there to see (and smell) the cover start to smoke and stink.
Looks like I need a sign too