I grew up in the US, so I have an American English accent, a northern Californian accent, to be more specific. Travelling through Ireland and Scotland was quite entertaining. I had a really difficult time understanding everyone, especially people with a Scottish accent, and even more specifically, the Scots that had a Glaswegian (Glasgow) accent. 
I also think it has been interesting studying at uni here in Sweden. Most of my English teachers have been educated with British English writing rules. I have had difficulties with some of the gradings of my papers due to this fact. I had to actually go to their offices and tell them, "Hello, I am American and this is the way I have been taught to write." They were like oh makes sense, I'll change the grade. 
I have also had a few English teachers here in Sweden that were from the US and I never had a problem with their grading based on my usage of English, haha.
Just silly things! 