As someone who wants to have meaningful interactions even if they are brief, it's super annoying when I just want to offer a compliment or joke to a stranger and they think I'm trying to talk to them. Are they so selfish that a little chuckle or "thank you" is going to break them?
For every person like you there's 500 dudes who want something from the stranger - their money, their body, etc. People are standoffish because they don't have the context that you do regarding the interaction and it's unclear which way it's going.
How does that make someone selfish? I'm sure there are judgements you could make against someone who would prefer to be left alone, I just don't see how "selfish" could be one of them.
For me, one of the main motivations is suspicion of ulterior motives. If it really is just "hey I like your hat okay bye" that's one thing, and is generally harmless. But usually when someone approaches me they want something, either they're selling me something, or asking me to sign something. It's not that the initial comment is necessarily an issue, it's guarding against people pretending to have an innocent interaction as a foot-in-the-door technique.
That's literally what the world is. It's the amusement park for all of us. Some of us like sharing our joy with others. It's up to you whether you are open to receiving it.
Oh, but I'm not opposed to joy or taking to strangers. I just respect that some may not want that for all sort of reasons, all valid to me, regardless of how superficial they are.
And notice the subtle difference: in response to your (IMO rather entitled) expectation that everyone should be open to talking to you, I said that the "world is not your amusement park", to which you responded shifting it slightly to "world is the amusement park for all of us" -- I agree with the latter, I just want you to not expect everyone behave like it was yours :)
Most people don’t mind someone initiating a casual conversation in a non threatening manner. Most will enjoy it, at least sometimes.
I’m happy for the author here, especially that he was able to shrug off these awkward interactions and move on.