While tecnically not a "matter of fact", there are still a few things my "friends" have said that I'd want to Face-palm them for..
"I dont understand why nintendo and sony dont just put all their games on the computer, it would be so much easier and they would make alot more money"...
"WoW has the BEST GRAPHICS EVAR!"
"I play WoW for 4 hours a day, and i still have a life"
And then theres the troll-like "gamer" freind of mine who spouts into a lengthy conversation on the virtues of Halo3 whenever the Xbox is mentioned... He also claims dual analogue aiming is much more accurate than the mouse and keyboard.
There are also a few from my childhood, mostly revolving around Pokemon..
"Dude, in japan they've made REAL picachus, they just die in 5 weeks"
"If you get all of the pokemon, talk to that game dev guy in and get the certificate he gives you, then you can go to bill and get into Bill's garden, which is all that blocked off areas you see in the game"
"You can join team rocket at Nugget Bridge, and then all the fences dissapear and you can take stuff from the safari zone, but if the guy catches you you have to fight him and he has all lvl 100 pokemon"
We werent the smartest bunch in the world back then...