Why do all americans seem to think we talk in a posh accent we all dow do that :)?

I just think its best all americans out there found out the truth, sure i can talk like the queen an the prime minster if i wanted to but i only do that on important phone calls because i just sound too snobby. Alot of people in england and all over britian talk with different accents! such as liverpool, manchester, blackpool, scotland, plymouth everywhere and alot of londoners talk like the eastenders lot lol - reseach- not like they got a pea stuck up thier nose. :) im not doing this to affend anyone im doing it to state the truth.. I myself am from the black country near birmingham alot of people would say is crap but i love my accent and the way i talk such as , things like - where ya gewin today, alright then here ya gew or here ya am. :) so just so americans start to know we do not all talk in such a prim and proper english accent i defiantly dow talk like that i talk how i'm brought up =D