How often do you make friends with total strangers? (In person)

Hello again ✌️

So, I've been living in Brazil for a little over two years - and plenty of people approached me in public places. Every couple of months or so. In many cases, we would instantly Gradually, they'd introduce me to their friends. Then I'd be friends of their friends. Etc. This is unusual in my country (Bahrain) - and I love it. However, I noticed I'd always be "the new guy" in their circles. They've known one another since high-school - or middle school. Even. They told me that in Brasilia (where I'm located), that's how most friendships are like. Meanwhile, their own experiences in Rio were very different. At least, according to them: I't's where this sort of spontaneous social life regularly happens.

However, other people have been describing Brazil as a "low trust society" - which makes me wonder how true this "spontaneous social life" really is - where ever you happen to live at least.

Thanks!