"You don't miss what you never had".
"If you strive for perfection, you attain excellence, and you will meet the standards, which are bare minimum".
That one I heard in my PLDC (Primary leadership and development course) E5 school in the Army
"IF the dog wouldn't have stopped to take a crap, he'd have caught the rabbit".
When asked a simple "yes" question: "Do fat babies fart?"