"Chuck" was literally kicked in the head by a horse when he was a child (he's mid-30's now; 36, I think), and he suffered a significant degree of brain damage as a result. He lives with his parents, and will never really be able to live on his own.
That said, he's the most wonderful guy, and there's just about nothing he can't fix on a car, or a home improvement he can't accomplish. The guy has an almost savant-like level of concentration. His Dad says he's always been that way. He rebuilt the transmission in his brother's Shelby in their garage.
I have no doubt that, given half a chance, he'd do a pretty fair job of fixing what's broken inside the beltway, too...