My endo does the same thing with the prescriptions. I think it's all about officialdom: OMG must adhere to strict identity checks lest someone get illicit estradiol! People at her office always call me Alyssa in person ... except the automated calls reminding me I have an appointment.

To hell with officialdom! I've been dealing with the university a lot lately. I am now Alyssa to: my lab computer network, another lab in the U.S. where we run simulations, campus mail servers, campus directory, and, oddly, campus libraries, which sent me a fine notice for haveing a reserve book out for an hour too long. I am <boyname> to: the campus billing office, transcripts, the foreign lab that maintains software we use and (login-accessible only) documentation, campus ID card, and the student health center.
The last one is really irritating. I had to go in because of a minor injury (no worries, I'll be fine), and I told them to call me Alyssa. The nurse that saw me was
really irritating, and seemed to use "quotation marks" when she said my "name," like "it" was a joke "she" was "in on."

It's amazing how much knowing my legal name changes how people treat me, and irritating as hell. Bastards.