The Titanic is no longer important and not worth fighting over. It's a recreational interest, but not for everybody of course so you have to allow that some of your friends could think you eccentric and might poke a litle innocent fun. Don't take it seriously - just return the favour and poke fun at their homes decorated with football or auto memorabilia or whatever!
Dude i totally agree, i hate how people are so ignorant and make fun of titanic because the movie is all they know. Like, when people say its not scary, and they tell me im a wuss or baby for thinking titanic was scary. They dont know ANYTHING! How dare they! Camerons film was okay, but people need to stop with the talk about it and wake up to the hard cold fact that Titanic ACTUALLY happened. Heck, some people still dont know titanic actually happened
It can be a bit annoying, sure, but I try not to get that worked up about it. I learned the hard way getting upset about silly things doesn't help anybody, especially yourself.
That being said, it's also cultural. Americans just aren't as interested or connected to history as other people. I'm amused that when I mention my interest in the Titanic story to Americans, they immediately remark on the Cameron film. When I tell Czechs, they remark about what tragedy the sinking was.