It surely kills time as nothing else can possibly do.
A says B
B replies
A says B
B replies
A says B
B replies
Scintillating conversation to be sure. Else why would any one any where for any reason continue to engage in it?
Perhaps because predictable is soothing and never a threat? And since we are unable to go anywhere or do anything killing time however we do it is better than just sitting being watching hearing seeing. I guess.
