It's overused sayings day! Here for your consideration: three overused sayings - pithy, but still true.
(1) The secret to happiness is not getting what you want, but wanting what you've got.
(2) The truth always comes out.
(3) The cure for anything is salt water---sweat, tears, or the sea. (OK, you got me - this last one is a quote from Isak Dinesen, and not a pithy overused saying. But I like it. And I think it's true, too.)