Well, I advise this, and I am a college kid, yes.
But the reasoning behind it? The fact that you should pay attention to? Are you wondering where it is?
Well, with good reason, I'm sure you do. I drive an automobile that isn't worth a tinker's cuss. Buying a gallon of gas at a time is all I can think of when I'm at the station. Just one, because you don't know when this thing'll end up at your house for the next week.
That's what I'm saying. If you buy gas, and your car is a broke down rusted-out box of shit, buy a gallon at a time. Why would you want to waste the extra $1.50 per if you don't get to take it anywhere?