How come you gotta beg for a bag at the gas station when you buy a bunch of candy bars and stuff like they can't just give you one?

Probably because they owe on them or trying to cut cost or the worker there is new and it isn’t in their routine yet. I remember when I was working at Taco Bell I’d often forget to give cup holders to large orders. I had so much going on and was never trained to do it.