Open problem
During a Sunday afternoon run I solve an open problem. I'm a genius.
I get home and put on the coffee. I stand in the door frame basking in my cleverness.
I notice a drop of sweat on the door-frame. I must have left it there when I momentarily touched my head against it.
Cleverly, I decide that I can get that drop of sweat with my shoulder. Leaning my shoulder against the door-frame, I jump up to wipe the drop of sweat with it.
Perhaps this was not so clever. Because I'm standing in a low door frame. I jump up and whack my head on the top of the frame. I'm an idiot.
Lying in bed with a sore neck, I realize that I didn't actually solve any open problems.