WHAT?! We've been pen pals for months and you don't know what Thunderdome is? Ok, admittedly, there are gaps in my knowledge of pop-culture stuff too. Like, I don't know who shot JR or what M*A*S*H is really about. Oh man, it's a good thing I'm sitting down. Ok, first, it's a reference to Mad Max: Beyond Thunderdome, which I really think you should watch. I'm not going to say that it's a great movie, though I think it's awesome and shaped my childhood in ways that it probably shouldn't have. Tina Turner is the bad guy and it's set in post-apocalyptic Australia, starring Mel Gibson. It's dope. If you really want to get the reference, you can click this link (no real spoilers). But! To get the proper context, I really think you should see the movie.
I've seen Mad Max: Beyond Thunderdome, just figured it was something new that I didn't know existed. You know some kind of Celebrity Death Match thing... You can relax, I've seen the film. Been a LOOONG time though.