I’m not ancient. Although my two daughters may think I am. But my parents raised me in old fashion ways. I was always taught to refer to people as “Mister” or “Misses” with their last name. I addressed my elders and people of authority (teachers, etc.) that way.
Because my parents drilled that so deeply into my brain, I still do that today. When corresponding with any of my customers, I always refer to them as “Mister xxxx” or “Misses xxxx”. Some customers ask me to call them by their first name. Most of the time, I remember to do that. Sometimes I forget though.
If I refer to you in a formal way, please don’t take offense. I remember most of the time when someone asks me to use another name. Old habits are hard to break. I’m indebited to my parents (now both deceased) for drilling the concept of respect into my brain.