I once went on one (only!) date with a girl who was a little dim. I was constantly trying to help her with her basic chemistry homework. She couldn't grasp anything. Anyway, being a little unsure of what to talk about, I made the casual comment about how humid it was since the water glasses had a lot of condensation on them. She then proceeded to tell me how wrong I was. She insisted that the water in the glass leaked through microscopic holes in the glass. Thus the reason for the moisture on the outside! We actually argued about it and I never convinced her.
A 16 year old girl, while eating buffalo wings, stated, "This tastes like chicken." Months later when someone else was joking about it at her, in defense she said, "Well, it does." It was then her friends finally got the point across to her that it was chicken.
There was once a guy who was having computer problems. He was constantly loosing vital information stored on his hard drive. The tech support lines were not being very helpful either. One day, a friend of his came into his office and discovered the problem with very little trouble. Our stupid friend kept his magnet collection on the wall about 6 inches from his hard drive.