There's a lot of weird accents here in the UK. Even cockney sounds odd, and that's local to London. In the same place you'll meet people from Liverpool, Newcastle, Birmingham, Scotland and so on, all with distinctive accents that are not so easy for your ordinary American or second language speaker.
Weird? Nah, but there is a lot of variation, and some of them can be difficult even for locals to understand.
However most of us naturally switch to some variation of RP (or as heard on the BBC) while interacting with non locals. It has often been said that there is more variation in the way that English is spoken within the UK, than there is in the rest of the world.
I once had an experience in the USA while sitting at a Restaurant bar and conversing with the barman. He eventually asked where I was from, presumably due to my manner of speech (in English).
I then went through the rigmarole of asking him if he believed I was a native speaker, or knew it as a second language. He picked native, but was unable to enumerate the short list of countries where I was possibly from, and could not guess the answer.
At no point did he try England. He was surprised when I eventually told him I was British, and from England.
It seems too many folk in the US expect that all of us sound like Hugh Grant.
