Eleven. That's all I got for the number 11. (He's one of my DJ homeboys- he's cool as a polar bear's toenails)
"I know for a fact...."
Very rarely when this is stated does the person saying it ACTUALLY knows something for a fact. Most of the time it's said to win an argument and the person only has, at best, a strong hunch about something.
Eight times out of ten, the information they are referring to has been gleaned from some great source like something a distant cousin mentioned while drunk, a television show that has been off the air for a few years, that one thing they saw that one time on the Discovery Channel or that movie they caught on TNT last night. Or maybe they got it from Wikipedia, that fount of accurate internet knowledge.
Sean likes this site better. 
If you find yourself with this gem on the tip of your tongue, STOP!
You are either in a stupid argument, arguing with an asshat who doesn't believe you anyway and/or you are the asshat losing an argument, struggling to save yourself from losing by trying to grasp the little bit of knowledge on a subject that you think you have.
Trust me. Stop it. You don't.
I know it for a fact you don't.