I am not Spock Sherm

Twice in the last day, people who know me a little but are not particularly close have called me “Sherm.” This occasionally happens both face-to-face and on e-mail, but I’m wondering if others take slight name mangling as a subtle signal about interlocutors. (Others misspell my last name, especially customer-service folks who find it hard to distinguish Dorn from Dorm on the phone, but Sherman is easy to spell.) I’ll answer to the name, certainly, but I’m curious how it is that people don’t listen when I introduce myself and don’t ask whether abbreviations are preferred.