His other idea is, perhaps they're all dead. If they were, that means they're all dead from different dimensions and times. But what if this was death? Stuck in a place like this, to show you all your flaws, and let out all your secrets, with no way out, and the closest you can get to outside is the rooftop. In any case, he doesn't look down.
All he knows is he needs some one to snap him out of this thinking, before he seriously considers jumping.]