Women are much more communal than men. In ancient times, men hunted and did other singular activities while women tended the home and the children. ‘Women’s work’ was very communal and required the help of multiple women to get all the nessary jobs done. Also, women process information, emotions and events by talking through them, rather than retreating to a cave like many men do.
Regarding women talking on a train or other semi-public place, no, we don’t think everyone else is interested in our conversation. We think that other people should go about their own business rather than eavesdropping on conversations that don’t pertain to them.