The man who is always waving the flag usually waives what it stands for.
If two wrongs don't make a right, try three.
. . . if you can tell the difference between good advice and bad advice, you don't need advice.
Expert: a man who makes three correct guesses consecutively.
Nobody can be perfect unless he admits his faults, but if he has faults how can he be perfect?
Everyone rises to their level of incompetence.