Things I learned at my father's knee, and other joints:

He sure talks a good fight for--someone who can't be relied on
He couldn't fight his way out of a wet paper bag for--someone who was weak or ineffective
Hang a right or Hang a left for--directions for making right or left turns while driving
It's six of one and half-dozen of the other for--choices having equal value (good or bad)

But here is something I have never figured out. Why do people when taking a dring of liquor sometimes say: "Here's mud in your eye." Obviously the drink is going down the throat (I hope) and it certainly isn't mud (hope again). So where does it come from and what does it mean?