Y'know I've often found that people who are extremely brainy seem to lack in common sense. For example, one of the guys I work with sent his daughter to grammer school, she got straight A's and is now in University to be a doctor. She rang up her dad a couple of days ago asking him to send her her voting card. He spent the next 20 minutes trying to explain to her that she votes for an MP for her constituency. Even though she'd had all the education she still hadn't got to grips with the voting system. She thought the new PM was selected via proportional representation! So, like I said, lots of brains = lack of common.
Whereas I, on the other hand, have the perfect balance. I'm not very clever and have little common. ......... well, it's better than having a lot of common and no brains at all!