This is a 2-in-1 question, I suppose. I type the way I do. I’ve always typed this way, but I’ve noticed when interacting with people (not on here) that people always think I’m far older than 19. They think I’m in my forties or fifties.
Also, I tend to type using full stops, which people may think are rude. When I’m typing a full sentence, though, I end it with a period. If I say, “He’s being an asshole,” (with a period), I mean that as a fact, not out of anger. It just happens to be ended with a period since it’s a sentence.
I’d say it’s more insecurity
I think it’s trying to understand society and his place in it. These aren’t bad questions. At a certain point you rather know where you fit and other people be damned. But at 19, your trying to understand how other people think still. You have your own thought process and are still getting used to other adults not processing information the way you do.