First, it's Grigori (Григорий) or "Grisha" for short. Secondly, there's quite a few mathematicians that have that look. I remember a funny story one of my professors told me about Campus Security not allowing him into a building because they thought he was a homeless person trying to get some food, before another professor called out his name and explained that he was, in fact, an eminent professor in the Math department.
That said, I sometime feel this way when I run into a professor on the BART or something. "Doesn't anybody realize they're in the presence of a genius?"
Wow, that reminds me of a lesson in humility I got once. I was doing math undergrad. The professors used to let a few of us smart-ass types hang out in their math department lounge where the order of the day was playing chess and Go, exchanging attempts at witticism, and avoiding work. One day I noticed a stranger, a shabbily-dressed little old man, hobbling around the room. I distinctly remember thinking: "What is that old guy doing in here? He obviously doesn't belong here. He looks like a bum!"
That said, I sometime feel this way when I run into a professor on the BART or something. "Doesn't anybody realize they're in the presence of a genius?"