Two specific ways in which my brain is broken (of the many ways that is):

1. I still will spell "friend" like this: freind. This happens more often than not. I have to say "i before e, i before e" to myself. Also, I always have to look up how to spell barbecue properly. I blame this on the fact that english is not my native language. Though I'll never forget that river is spelled with a 'v' not a 'b' because my oh so kind first grade teacher pointed out that "in english we distiguish between the v and b sounds." (Nice.)
2. I will insist that 9 is a prime number even when shown proof that 3 is the square root of, or that 3 x 3 = 9. I got that wrong on every "speed math" test in elementary school.