My sis in law's name is Kathy. When I asked (many years after they were married) if her "real" name was Katherine, Kathleen, etc., she said "No, because her parents knew she would be called Kathy".
Parents, here's a hint from someone who know
It is a pain to be called by your middle name for decades but when you go into the "real world", you are called by your first name. People would ask me my name and I go uggh??