My DH’s name is one that had a well known/obvious shortened version - similar to Nick for Nicholas or Sam for Samuel. He never, ever uses his full name. Neither does the vast majority of his friends, family etc. He would introduce himself using his shortened name to anyone new.
Fairly lighthearted but I find it really weird that both his parents use his full name, plus a few friends. Isn’t it a bit rude to insist on using someone’s full name when it’s not their preferred name? If you are someone that does this - why?!