What are your favorite/most interesting sayings, aphorisms, metaphors, similes,etc.

Badsport said
When kids think they are know it alls, I counter with "Look I know more about being young then you do about being older". Stumps most of them.

ocdart said
As is typical for most all teenagers, my son thought he knew everything. I finally got fed up and told him, "You think you have all the answers, but you don't even know the questions yet!"

When I worked in HVAC service, a woman had a magnet on her refrigerator:

"Teenagers!! Quick!! Move out now while you still know everything!!"