Some time ago, I had a dream, where really weird things happened, so I did some reality checks. I looked at my hands, but I had 5 fingers, just as usual. Then I tried to stick my other hand trough my palm, but it didn't went trough. So I fought I'm not dreaming. Is it possible, that I did the reality checks in the real world so often, that my brain learned what happens when I do the checks, and carried that knowledge to my dreams?