Non-wasted time is getting something done that I needed to, or doing something I wanted for fun. Like museums, studying languages, or playing with my microscope.
Wasted time is, having to rework something that should have been done right the first time. Explaining something more than once to someone else. Having to take on and plan out a project because the people you work with are incompetent.
By most people's definition I don't do much else than waste time. Myself, I don't think I waste much time. I guess wasted time by my definition would be "to do something not worth doing from any perspective". I don't remember when I did something that fits this definition.