Try this: the next time you go for a run, wave at the people in the cars who pass you.
Be first. No words need to be exchange, just a proactive act of recognition.
Here’s what you will find:
The vast majority of people will wave back.
There’s a micro-lesson here: in the right context, without asking too much of them, most people are friendly.
Unfriendly behavior tends to come from overworked, stressed, exhausted, uncomfortable, or desperate people.
No one wants to be unfriendly; they just don’t know how to get out of their funk. Think of them as temporarily diseased, momentarily addled.
But that’s not most people, most of the time. Just figure out a win / win dynamic, and you’ll see friendliness everywhere.