Your name is mud
You can catch more flies with honey than with vinegar.
You can’t make an omelet without breaking eggs.
You can’t teach an old dog new tricks.
You can say that again
You show me the man and I’ll show you the rule.
Your Guess Is as Good as Mine
You can lead a horse to water but you can’t make it drink.
You can’t unscramble a scrambled egg.
You can’t have your cake and eat it too.