Whiners usually play alone.
The teacher can always tell when you did your homework on the bus.
Nobody notices it when your zipper is up, but everyone notices when it's down.
It's easier to see the mistake on someone else's paper.
Believing in the Tooth Fairy is easier than trying to figure out how else the money gets under your pillow.
Every piece of the puzzle that doesn't fit gets you closer to the answer.