Well, i do live with very little stuff for some years now, but since i'm in Brazil i do have some limitations. For example, i live in the cheapest place i can live with safety. For you to be safe in Brazil, you gotta choose an expensive neighborhood.
When you consider living in a truck in Brazil, you'll get robbed the first night. That being said, i think more than 15% would be happy with a minimalistic life, as long as you live in a safe country and you get the mindset, you realise what it is all about.