I definitely wouldn’t say it is selfish by any stretch of the imagination. But I can see how someone would get offended if you forgot theirs. I’m horrible with names too. I’m just up front with people about it. If anyone gives me a hard time I tell them I’m face blind. That usually ends the discussion or them trying to give me tips. I agree saying someone’s name over and over feels creepy. I know why they do it, but it comes off super unauthentic. I’m fine with my own name, but I have a very common name that is always shortened. For some reason it makes me want to crawl out of my skin when someone says the shortened version with my last name. I can’t say if it’s a common ADHD thing. But you can add one more ADHD (probably somewhere on the spectrum) person who is in agreement with you.