Try going moose hunting in Newfoundland and understanding some of them! I didn't have a hard time, but had a buddy that couldn't decipher a word.
Ain't that the truth!? I found the Newfies hard to understand at first but after a while I was able to follow what I would describe as a "cadence" to their speech. Great people.
My wife's college friends had a hard time understanding me sometimes. Most of them were from downstate and I speak a sort of local gibberish I call "Hamdenese". My Mother is from Hamden, NY and they had words and phrases around there that I was surprised to find aren't normal anywhere else.