This is really a corollary of know your dreams. You could get rid of just about everything you own, and live in a practically empty space. Think of Jack's parent's home in Brokeback Mountain. Or you could get by with just enough to fit in a backpack.
Those are interesting possibilities, but for me they aren't realistic. (Maybe they are for you though. Tell us about your experience!)
Just remember that your goal isn't to get rid of everything in your life. It's to get things out of the way of achieving your dreams.