I also considered the term "character building" to describe activities that did not qualify for my resume. Unfortunately, much of my character building did not come from even mildly significant stuff I have done professionally but from recreationally like going to Pakistan or Mezcal or running Extended Lost Boys.
So the new term is "biography building". I have worked the past three weeks for my uncle at Janzen's Greenhouse a 56 year old business. A few more weeks will be all that I am here. It's too short for a resume, it's not really building any character. Everything I've learned socially (character) I've known so I haven't changed at all. I also used biography instead of autobiography because it's more general, and I'm a dreamer...
Everybody that I know has biography building experiences. Times when you are out of your preferred element, but not so far out of your element that your character changes. Things that are significant, but only significant to people who know and care about you. Biography building is doing those things you enjoy to make your life more interesting and are not profitable. Things you do with your menugas. Although those may be character building as much as they are biography building.
A relative said to me last week "I'll be curious to read your biography to know what it was like to live with two deaf people." A short preview of living with two nearly deaf people, it's loud. The other inspiration he gave me was the idea of having a biography. A way to pass of stories and information to future generations. The point being, write it down, tell someone, keep a journal, strive to pass on something that might help people in the future. I heard a line in a movie once, "history doesn't repeat itself, but it rhymes a lot." I think that we make many mistakes similar to mistakes others have made. We can learn from others mistakes and make wise decisions in our life. If 16 and Pregnant on MTV isn't a lesson in safe sex or abstinence then I don't know what is.
So pass on your knowledge and experience. Even if it's not interesting now, in 50 or 100 years just about everything from today will seem interesting.