"Well, I dunno if it was that..." Even if it's- actually probably true. At least in their orphanage's case. Joker doesn't really care to think on it, anymore. He tries this best to avoid it, as a matter of fact.

Oh, new question. Joker grins and gives a shrug. "The whole ghost limb thing, right? Sometimes! Sure is a pain when it's early in the mornin', I can tell ya that much." Has he fallen on his face while still groggy and thinking he has his prosthetic? Maybe. That's a possibility.