Kind of. In England we have many, many local accents/dialects. Most people speak their ‘mother tongue’ as a local dialect. Some of these dialects are so different to what you would think of as English (this is a dialect called Standard English) that you wouldn’t understand most of it. Even English people don’t understand other English dialects perfectly, only their own and maybe some others depending on how familiar they are with them, like neighbouring dialects which are closer to their own. Then consider that England is joined onto Scotland and Wales, which not only have their own dialects of English, but actually their own completely different languages.
So its the same effect as if you’re speaking a second language exclusively for a long time and then you can speak in your mother tongue again.
Kind of… Standard English is the reference dialect of english (used to teach foreigners) and it’s what received pronunciation (queen’s English/posh sounding) accent uses.