What really pisses you off?

1)When people form a circle group in the middle of a fucking 2x2 hallway just to talk. They create an impassable barrier just to socialize and then I gotta waste my time and energy pushing people to get to class.

2)People walking slow. I generally speed-walk all the time. When I'm on the sidewalk and people are just taking their sweet time I usually cough a bit to let them know that I'm still there =/

3)Cell phones in the middle of a conversation or doing something together. I hate this the most. If somebody pulls out their cellphone while I'm talking to them I might as well talk to a fucking wall and there'd be no difference.

4) Music. Have people never heard of headphones? Nobody wants to hear your stupid shit when they're trying to sleep on a public bus.

5)The chewing thing as you mentioned.