A conversation between my coworker and I:
Me: "Where are you staying?"
Her: "Uh... the Grand Shanghai Hotel, but I don't know where it is."
Me: "Oh, I have an atlas; I'll look up the address."
After looking in the atlas, I realized that what's listed in there is complete nonsense.
"Oh," I thought to myself. "I'll just wake up and look in the real atlas; that'll list it for sure!" And so I did.

Only after awakening did I realize the problem with this logic.