I was just sitting at the mall taking a break from mall walking. A man walked over to me when I wasn’t even looking up. He said "I haven’t seen you here before. " I said I wasn’t really here to talk to people and got up and walked away. He said he would leave, he may even have said sorry. I said I was ready to leave anyway. In retrospect I think he may have just been slightly mentally challenged so I wish I had been a little softer, he did not turn out to be aggressive. Looking for suggestions on something still clear and firm but more polite? This scared me for some reason, I think how fast he walked up and sat down near me.
Editing to add a key detail, he sat down close to me which is probably what made me more nervous than I would have otherwise been. I appreciate all the thoughtful feedback I’ve gotten and interesting discussion.


That depends so much on where and when you are. I’m older than social media and no, strangers didn’t walk up and say hi in my culture/s. There were plenty of places that sort of thing was acceptable but they were places with an implied invitation to socialise, not the street.
The post doesn’t mention being on the street, it mentions walking around a mall and taking a break. Malls have historically been social locations since their inception, especially among those that choose to go there without the intention of shopping at the stores located within it. Nothing wrong with wandering the mall, but other people may think you are there to socialize if you aren’t shopping… Especially if you are partaking in their favorite activity.
Oh well, it’s a marginally different situation. Might as well just discount my entire comment. It’s what I’m going to do with your forest-for-the-trees comment rather than engage any further.
Their comment directly responds to your point by claiming that the mall, where the OP’s incident took place, is a “place with an implied invitation to socialize”.