Never look a gift horse in the mouth and other sayings...
 

Ever wonder what the fuck some of these mean?

Never look a gift horse in the mouth. People say it all the fucking time, but do they even know what it means?

Apparently, you can tell the age of a horse by looking at its teeth, so it's considered rude to check the age of a horse if it is a gift to you.

How about some of these what do they mean or come from?

You must be off your rocker (crazy)

He fell off the wagon (drinking)

Knock on wood (luck)

Any others?