Coming to Boston for college in the early '60's from a Chicago suburb, having learned to speak standard newscaster American, I was in for a big shock. I couldn't understand many people, "townies", for quite some time. John Kennedy was president and the album "First Family" had been released a couple of years earlier, so I had heard the Kennedy Boston Accent, but never heard the range of accents until I got to Cambridge. Asking for directions was especially challenging. My freshman year I tutored a high school student from Southie. His family invited me for dinner at their home. Not quite like being in a foreign country, but close.
The Seth Meyer parody was a lot of fun for me. And, of course, cars were not allowed to be parked in Harvard Yard.
Going up to Vermont and New Hampshire was even more of a challenge.
I remember the first time I went to the mountain of North Carolina. Could not understand half the words they were saying. But adaptation set in and it was not a problem later.
I also took my wife to London and she couldn't understand street accents of merchants either. But having lived in UK, it was not a problem for me so I did the "English to English translation."
my family has "family" from near everywhere on this planet, we've sponsored family from some pretty sad places to live on this earth ... yet, it's funny, at family gatherings how different dialects all seem to sound exaggerated. those little mercies ...