I get a kick out of my own personal 20 year old (everyone should have one - they come in great when you need yard work...or an illegal copy of Norton...
). He can't seem to realize that I've already been 20. Heck, I've been 30 AND 40, lol, and since he's never been 20, I might possibly know just a wee bit more about life, business, money, etc. than he does.
And of course, I knew everything when I was 20 - just ask my Dad. :P