Before you trade sandwiches, check between the bread.
The path you're on looks different when you turn around.
It's not enough to be able to spell "magnificence" in your bedroom. You have to be able to spell it at the microphone during the spelling bee.
Nobody notices it when your zipper is up, but everyone notices when it's down.
Don't expect a stranger to wipe your nose.
Don't say "The last one there is a rotten egg": unless you're absolutely sure there's a slow kid behind you.