I'm going to tell a customer she is a moron instead of answering her simple question
Why would you tell her that?
I'm tired of dealing with customers, so I want to fire back and tell her that her question was idiotic.
Simple questions seem to bother you. You have one job to do and that is to be courteous, so why stop now? You might get fired if you are reported as a rude customer service agent.
It's only a single customer, and I don't care if this costs me my job.
You have taken on the responsibility for assisting customers as a service rep and being rude to this customer breaks that contract. Find a way to let go of your impatience and just be there to support your client.