My future MIL is like this. According to her, she not only knows everything, but she's also the funniest woman on the planet! Every story from her ends with everyone around her in hysterics because of her funny (but most of the time off-kilter and a little gross) jokes. And if you disagree with her, she closes her eyes and shakes her head from side to side saying, "Nu-uh, no, no, no!" like a child. This is truly one of the only problems I have with her, for the most part she's a good woman who means well, but it really gets annoying when trying to have a conversation with her.
One time, FMIL was talking about something silly/stupid her sister did, then said, "Well, what do you expect, she's blonde!"
I turned to her and said, "Hey, hey, hey, not all blonde's are stupid, I'm blonde!" (A darker blonde, but still blonde. Her sister is actually a dyed blonde, whereas I am a natural blonde.)
FMIL then said that I wasn't in fact blonde, but my hair was reddish in color!
A little bit of background: I temporarily dyed my hair a brownish-red three years ago, it lasted, all in all, about 6 months but the red quickly faded from it and was basically just a brown. Fiance and I have been together for a total of 6 years at the time of this conversation.
I tried to tell her that I was in fact blonde and had been blonde for my entire 25 years of existence (minus 6 months three years ago), but for some reason she refused to believe it! Fiance finally just stopped me by saying his mother is color-blind (which I don't think is true), but I'm still mystified as to why she refused to believe me when I tried to tell her what color my hair is!