I find that this is just naive. A lot of people aren't very comfortable sharing things. I'm relatively open, and don't mind telling people about how some dumbass swung open his car door into the bike lane when I was riding into work this morning. My less open coworkers like the idle conversation, they smile and follow the story -- they just don't have much to add, or any desire to share their own stories. So what can you do? Force a conversation? Every once in a while, sure, but it seems to me it's better to let them speak when they're ready.