Because no one is a genius 100% of the time.
We can build computers, design websites, write sonnets, read several languages, and solve differential equations. But that one time when we had to put together some IKEA furniture? Let's not go into that here. We'll write it off as non-Euclidean geometry.
Nothing is more humbling than discovering a situation in which your immense body of knowledge is completely useless. Just because you have a PhD in Chemistry doesn't mean you can bake a soufflé. And nobody wins at Trivial Pursuit without at least knowing something about sports. (Luckily, sometimes it's about fencing.) This shirt says, "I'm a genius, but I recognize it's only applicable periodically to my life." Oh, and, "Also, I dig chemistry."
The chemical formula for genius (okay, it's not... but it SPELLS genius...), Germanium, Nickel, Uranium, and Sulfur, printed with their atomic properties in white on a black, 100% cotton t-shirt.