Yup, in sociological terms you are performing a very important societal function there; sustaining
weak ties.
Chatting amicably with strangers or people we don't know well is reassuring and educational.
If we spoke and interacted solely with people we know, we'd be socially isolated and possibly under coercive control of some sort.
This is achieved by cults and extreme religious communities through the permitting of only
strong ties.
Humans need a mixture of strong and weak ties to function well in society.
Weak Tie Theory - justifying gossiping with randoms since 1973.