Fellow nerds, I need your attention.
Actually, I need everyone's attention. But for reasons I'll lay out, you're my main audience.
I need you to tell you something important, something that you should in turn teach others. It's a great lesson in being a cool person, and it goes like this: "Let people have their stupid thing."
Now let me explain what I mean.
If someone you know likes to play video games, board games, live action role playing games, fantasy football, actual football, collect clothespins, shoot guns (at targets), watch Doctor Who/Firefly/professional sports/reality TV . . . in short, if someone you know likes doing something that's not harming them or anyone else, let them have it. Don't crap all over it just because you don't happen to like that thing. Accept that their amusement is not the result of some vile corruption inside them, but just a preference.
Nerds, here's why this is especially important to you. As a natural enthusiast, you've probably been highly subject to negativity from people (by which I mean *ssholes) who don't understand the objects of your obsession. If you've had time to get well clear of high school, you know by now that those people were wrong, and too boring to understand you. If you're not free of school yet, memorize the previous sentence and bind it to your heart.*
But if you've known that burden, you need to be especially sensitive toward it. What you don't need to do is repeat the mistakes of others, calling out fellow nerds for being ever so slightly nerdier than you. If you don't get it, aren't into it, or can't see what's so great about it, then just let it go. Everybody's got some stupid thing they like. Just let them have it. Support their right to enjoy their leisure time.
*With a sonic screwdriver.