We all own t-shirts. Most are plain but a few probably have some kind of spiffy logo. It could be a souvenir from your last vacation emblazoned with a castle, or some palm trees, or a mountain. It might be the name of your favorite sports team, or school. But if you're really lucky, it's got some quirky logo or phrase that will leave the majority of people bewildered.
Congratulations! You are the proud owner of a Geek T-Shirt.
The beauty of a Geek T-Shirt is that it instantly conveys the geek cred of the wearer. Other Geeks will see your cool shirt and think "One of us!" just like birds that sing the same song to find each other, only this is with cotton, and ink, and maybe something from the periodic table. They will offer up a smile and possibly comment on your innate coolness with a witty t-shirt related comment like "I miss Captain Tightpants."
If someone doesn't get your shirt (gasp!), then they have two choices. They can walk away wondering or they can ask. This is a tricky situation for the wearer because you never know how they're going to react to your answer. If you explain that Serenity was the coolest sci-fi show ever, that it was cancelled too early and that your shirt is the perfect homage to bad-boy-gone-good Jayne, there's a chance they'll run away. But if it's a fellow Geek, they're going to roll their eyes, (facepalm), and acknowledge they haven't had their morning coffee yet or they'd have know that right away.
I do have one caution for those of you proudly wearing your Geek T-Shirts. No, I'm not going to tell you that you run the risk of mockery in the form of strange looks from the norms out there. Who cares what they think? Surely not someone in a Geek T-Shirt! My warning is this: Beware the UberGeek. This is the guy that will see your Friendship Algorithm Flowchart shirt and start arguing about why it's not entirely accurate. He is unstoppable in his conviction. If this happens, just smile, nod and slowly back away. If you're really lucky he won't follow you right out the door.