Did you check your belt at any point during those 40 minutes, or did you just keep patting your pockets and looking around the room? I ask because I do the exact same thing with my keys, and I swear my brain just refuses to check the one spot where they actually are. There has to be some kind of name for this, where your eyes skip right over the thing you're hunting for. What finally made you look down, or did someone else have to point it out to you?