I always believe that in life, we have a lot of acquittances but few friends. We encounter so many hi-bye "friends" that people think they have a large social circle, but that's not the case.
The few friends I have, when we do catch up physically after years sometimes starts rather formally then the conversation just flows and the time just melts away. I try to make the effort to connect and have no expectations as I understand we all have issues to deal with.
I think the US culture is geared toward the hi-bye approach, where people ask "how are you?" and then walk on before even getting a response.
That's the Aussie culture too sadly. I have experienced numerous times whereby people just assume you are saying "How are you?" and reply "I am good, thanks" when I said something else.....