I never pay it forward at coffee shops
What do you mean by pay it forward in the context of a coffee shop?
At my coffee shop it's fairly often that people will pay for the next customers coffee, but I've never once done that for another person, even though it's happened to me plenty of times.
While it's not demanded of you to pay it forward, it still common courtesy. I think you should take these nice things that people are doing for you and learn the pay it forward. It would make you feel better about yourself.
If that's the case I can just make sure I'm the first in line and not have to worry about paying it forward.
You could go about doing it that way. But is it really worth it in the end? All you're doing is paying for the person behind you and you may even be saving money.