I grew up in the Midlands. Born in Sutton Coldfield and raised 'til I was 14 in Lichfield. Both horrible holes but at least Lichfield has a beautiful cathedral to improve the place. Anyway, I used to have a really strong Birmingham accent. When I was packed off to boarding school at the age of 8 (I loved it, best time of my life), I was fairly mercilessly teased because of it, not in a particularly bullying way, but because everyone else had a generic Posh Public School Accent (Public School in England means private school, by the way).
After 5 years, the Brummie in me had pretty much disappeared and I now have that generic Posh Public School Accent (PPSA). The Brummie comes back when I go back up there and particularly when I go to watch The Greatest Football Team On Earth, West Brom (boing boing). It's difficult to be taken seriously shouting abuse at the referee and the other team when doing so in a PPSA :)
The problem with the Brummie accent and its many variations is that people who have one sound, well, thick. Stupid. Dense. Personally, I think Scally Scousers from Liverpool sound much more stupid, if you can understand what the hell they're talking about in the first place whilst they steal your wallet, hubcaps and anything else not nailed down, but perhaps I'm a bit biased. After all, the study came to the following conclusion:
"The study into dialect and perceived intelligence found that people who said nothing at all were regarded as more intelligent than those with a Brummie accent."Oh dear.