Good question. Of course, you didn't know their cultural "givens" also...

My ex wife and her tribe were not aware of Elvis Presley. The best reason I could think of is that Presley never did an African tour. On the other hand, the late singer Don Williams went on safari in Kenya and also did a tour while he was there. Everyone had his music. Riding in the matatu they would play his music and say "he is called Don Williams."

Just a note on Kenyan parlay here. They always say "he is called" where in America we say "his name is."

Not a relationship per se but I had to teach an octogenarian who had never touched one, how to use a PC from the ground up, from the concept of a mouse cursor and windows, to gaining the coordination to see and click on tiny boxes, and then make it easy enoigh for him to telnet remotely into another music store location and use their POS software. The man once opened for Buddy Holly. Talk about new tricks for old dogs.

Next time you have to tell the story of the good Samaritan make sure they follow up with this salient point about the story's racism ?

I found out through a friend who knows someone who grew up in an evangelical community that this person still thought Jews had horns.

My new roommate has not seen Harry Potter, Lord of the Rings, OR Game of Thrones. We have A LOT of watching to do ?

I am a foreigner, so I might be involved in such a situation, on either ends. I still do not know some of the things referred in the comments below. I am into music, so fairly familiar with bands and artists. Football is another matter!

My late partner was from a Moslem country (Iran). She never believed and when she came to the US had no idea of Christianity or any other religion. She thought they were all silly even though her family were practicing (sometimes) Moslems. However, after coming here, at 24, she picked up the cultural norms immediately.

My 21 year old son did not know what "Let them eat cake" meant. Also about having to go home before your coach turns into a pumpkin.

I introduced my British neighbors to catfish & hush puppies; they were also unfamiliar with bisquick. It was great to be able to do that!

Relevant XKCD: [xkcd.com]

My ex was like someone raised on another planet. He'd not seen any popular movies, read any famous books, or listened to any famous or popular music of the US culture, even though he grew up in the US in a well-to-do family, and was an airline pilot.

His mom was fanatically religious, so he did know the most well-known Bible stories.

I grew up in Haiti with American missionaries, and considered myself culturally clueless, but compared to him, I was a Valley Doll.

You will have many long delightful hours ahead educating your gf into the background story and music of LZ. You will probably find quite a few others to introduce her to after that!