In the past I had trouble with calling the other persons by their names, too. I was like "Hey! ...", as been already described. Now I'm 38, I have much less trouble saying "Hello, X" or "Hi, Y". For many years I didn't know the proper name of most of my relatives. I'm terrible with names, so the reason why I didn't use names must have been the fear of mistaking them, I guess. Unfortunately, it had happened to me a couple of times. However, I don't make up nicknames, in fact, when others at my workplace would use one, I wouldn't use it, even when I know it perfectly. Rigidity? Oh, once it has happened that I used one, and my colleagues said why I said that. It was too confidential. I'll never learn it. Perhaps that's why.
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Another non-English speaking - DX'd at age 38
"Aut viam inveniam aut faciam." (Hannibal) - Latin for "I'll either find a way or make one."