I have a few that I live by
"F--k em if they can't take a joke"
"You only live once so enjoy life while you're here"
I'd rather regret things I've done than wonder about the things I didn't
Bene vixit qui latuit (one who lives unnoticed lives well) - Ovidio
Trust was a nice guy, but Don't Trust was better.
Money doesn't give happiness, but all the remainder.
Sure. Just as much as the quote from Davy Crockett from the OP!
But if you really want a motto:
"Not to understand a man's purpose does not make HIM confused!
Here is another good motto:
The difference between a Wise Man and a Fool is the Wise Man knows more than he tells whereas the Fool tells more than he knows! ::