Well, in my case, in addition to giving my my dad's first name, my parents called me by my middle name to distinguish us (a not-unusual practice in families originating in Kentucky/Tennessee; I'm damned lucky they called me Mike instead of Jim-Mike). So for all intents and purposes, my legal middle name is my actual name. It's what I identify with me. That programmers don't get that is a continual source of irritation in my life.