What life lessons have had the most impact on your characters? What has been the impact of these lessons on the wider society around your people? When has a lesson been too painful for a character to cope with?
How has experience shaped your characters and are they in the position where they can help others avoid making some of the mistakes they did? (Do the others listen to them? Sadly it is always the case not everyone listens to good advice and some people really do have to learn their lessons the hard way).