It's entirely possible that I notice more about my surroundings than nearly anyone I know because when you're fat, you're constantly on the alert for things that will cause you social stigma. And, because you're fat, you blend into the background as much as possible. Watch the heavier people around you. I'll bet (A) they move like ninjas (B) you've never noticed that before. That's because when you stomp around you're being loud. If you hear them walking it's because they're gigantic hippos.
I know one guy who is more observant and quieter than me. He's also heavier by far.