I'm a northerner. I will chat to randos. But I know the times not to. Someone enjoying their breakfast and playing on their phone/reading a book, leave them in peace. Someone at a bus stop panicking they lost something, I take a calm practical approach and try and help.
Same here. If I am sitting at a table unoccupied and someone comes to sit at a neighbouring table and they make some small talk then I will more than likely respond and have a conversation. If, however, I am clearly and actively engaged in something - whether it's reading a book, working on my laptop or just checking mumsnet on my phone - then it is rude of them to interrupt and expect that they are entitled to my attention when I do not owe them anything.
I have lost count of the times when I've been stood at the bus stop clearly on the way home from work - uniform on, headphones in - and someone (usually, but not always, a man) has approached me. One time a guy literally waved his hand a couple of inches in front of my face when I didn't respond to his question, that I didn't hear because there was a crowd of people and I didn't know he was talking to me. When I have taken my headphones out, assuming they are going to ask a question about the bus schedule/times etc, they have just wanted to make random announcements or banal chitchat which I have no interest in. I have just finished a 10hr shift in a supermarket where I have to be nice to people all day, even when they are being dickheads, so I want to be left alone now because nobody is paying me to be nice and available to strangers who want attention until 10am tomorrow.
I also find that a lot of people confuse alone with lonely and don't seem to understand that just because someone is by themselves doesn't mean they need or want company and that they mught be enjoying the peace and quiet. I love doing things alone, sometimes because I don't know anyone else who would enjoy the activity and sometimes because I don't want the distraction of other people, and I am entitled to want to be left alone by strangers regardless of who I am with.
My sister really can't deal with my solo "adventuring" to the nearest Costa because she is the kind of person who needs to always have someone to do something with them, and if nobody is free then she won't do the activity alone, even if it is something she really wants to do. From being a child whenever she started a new class/activity she would not go unless either a sibling or friend was attending too whereas my brothers and I were all more than happy to go off alone and if we found some friends along the way that would a bonus, but not the main priority.