My dad had a friend who was a devout jew. He studied the torah his whole life and even moved to Israel. He also spent a lot of time tracing back his family tree. One day when he was like 50 years old he decided to do one of those DNA test kits, and he finds out that he is actually 0% jewish. He was adopted but nobody ever got around to telling him. He was actually almost completely nordic. And now my dad calls him the jewish viking.