I had a little more Irish than I expected. Turns out that there were several very distant ancestors (English, Scottish) that had just a little bit from very distant ancestors of theirs accumulating in the extra percentages.

I also had some pretty surprising amounts of french for thinking I was not french AT ALL. As it turns out I had a 6th great grandma who identified as German because she was from the region of Alsace before WWI. Al of her paperwork said German but by today's standards she would be considered french.

It could also be a name change situation. My sister married a man who thought he was fully french with a very french sounding name. She did his ancestry and it turned out he had a very distant ancestorswho had moved to France from Germany to a town with someone as the same last name as him, so he changed his name to sound more french and to differentiate himself from the other family of the same name. Sure, he was still a little french (from his family living in France for a generation or two) but he had a good chunk of dutch in there as well.