Am I saying, then, that most people aren't interesting? Of course not.
I am implying it.
So you're left with two choices: Either you wall yourself off from non-geeks entirely, or you build a set of mental filters for conversing with them. This second option may seem disingenuous, as though you're holding back a part of who you are. But the truth is that it's just another of the courtesies that make human interaction possible.
Think of it like this, you wouldn't go to China, begin speaking English, and expect anyone to know what you're talking about, would you? Well trust me, if you're at a non-geek party and you start talking about Delta Squad, you are speaking Chinese.
But secret option C is to realize that, at any given party, there are probably at least a couple of other geeky people who are quietly thinking about robots, hobbits, or ninjas. And if you can divine out these individuals, you can develop your own little side conversation that eventually becomes a really great game of Catan!
My advice: Invest in some geeky t-shirts. Nothing too obvious, in fact the subtler the better. You want to wear something that other geeks will recognize, but regular human beings will overlook.*
*If you do get questioned about this, it'll probably be some dopey looking meathead guy. It's cool, just tell him that the shirt"an inside joke with my pledge class". He'll nod and walk away.