It's also her job to be polite!

To an extent. If OPs RBF is bad enough, the cashier probably felt like they had to explain.

That was immature on her part to say "jeez" and show outward frustration on customers.

Well do you have a loyalty card?

She should be polite regardless of what you said/what expression you were making.

People are so quick to judge, anyway isn't it apart of her job to be polite

I know how you feel, OP; strangers have commented on how pissed I look on more than one occasion. I've gotten into the habit of shaving my eyebrows and drawing on less angry ones with Sharpie. Now I walk around with a perpetually sincere yet inquisitive look on my face. Well you're at it, you can also draw eyes on your eyelids in case you want to rest up during a particularly boring conversation without offending anyone.

*While

Also, you still look pissed, me.

I have a perpetually depressed looking face. Better than angry, I guess?

Just clicked on your profile to see if you actually looked pissed

"Just"? JUST?! I thought what we had was special, #17!

This is the greatest thing I have ever read.

I would explain to the lady that you didn't hear her and your face naturally looks angry.

I get things like that a lot,it's the resting bitch face syndrome!

Same thing happened to me last week . Feels bad man

I know the feeling OP; I have a naturally unhappy looking face so people always ask me to smile in group photos, but I thought I already was smiling.