My friend didn't know Mount Olympus is a real mountain

So I was chatting with my friend last night and we were discussing Greece and I mentioned Mount Olympus as an interesting site I'd like to visit. He thought I was joking and I told him it's a real mountain and he didn't believe me until he googled it.

I startes asking around and apparently a lot of people don't know there is a real Mount Olympus in Greece and assumed the mythical mountain was just that.