Simple lifeused to refer to a kind of lifestyle——a person who lives in the countryside, does not own many things or use any modern machine. He just lives in a small cabin and enjoys his simple life.
To me, living a simple life does not mean living a boring one,a lazy one, or an average one. And definitely not an easy one!
Living a simple life, you can make the active choice to include/exclude certain actions and habits from your schedule as you like.