I read an amazing thread on another forum:

http://ask.metafilter.com/14668/

Name and describe one experience in your childhood that has has had the largest contribution to the person you are today.

I figured people here may be interested in answering it too. I put the title as it is so people know and can avoid it if they aren't interested.. I think that people who play chess are likely to be interested in this type of thing, and willing to think about something like this in their own life.