I have a 12-year-old stepbrother whose friends like me too so they often tag along when we hang out. I've had them say "That's the guy/thing from Fortnite!" (Or other random games) so many times. I've had to explain several times that everything in that game is from other popular games, movies etc. (As far as I know, never played it myself).

It's fine when it's some random old meme or viral thing that I wouldn't expect them to know, I just see that as a chance to show them what it comes from. They've become fans of stuff like the peanut butter jelly time song with the dancing banana, crazy frog, Tay Zonday (chocolate rain guy) and more.

But way too many times they've said that for things I know that they know what the original characters are from, it's just that they mainly know those characters from fortnite or whatever so that's what they think of. I tease them for it, in a playful way of course, but it does get kinda irritating.