When I was in grad school, a bunch of us were at the house of a guy with an invisible fence for his dog. Someone wondered if it was cruel and that led to each of the grad students there except me putting on the dog's collar and then crossing the fence. (The consensus was that it really hurts, but it isn't agonizing.) At the time I knew that not shocking myself was, in some sense, the smart thing to do, but in retrospect I regret being a boring dork.