I get that some American accents are hard to understand, but at the same time, have you heard Glaswegian? I mean really. I think half the reason we can't understand some American accent is because we never hear them. So America should get on that. :P

Also, Good Will Hunting is regional American accents? Of where? Where's it set again? Detroit? Chicago?

I guess that's a thing too. If you speak the same as the people on TV you're less likely to realise. Same way as having parents with different accents to your own.

And yeah, it's proably a brain thing. Like that moment you realise that funny squiggle infront of the Disney logo is actually a D. :P