Well, he can't say as he understands that, not completely, but it's not the first time he's been faced with trying to wrap his mind around a strange and new method of travel. It's easy enough to accept, given that. Still, he has to wonder what happens if you can't figure out where you're going. Is it like the TARDIS, where you wind up places you'd never intended on going to?

"What happens if ye don't?"