In my opinion, it's better to do something than nothing.
But that doesn't mean you can't take naps, or watch TV, or just goof off. I think it means you can do those things as long as you are conscious of doing those things and view them as either rewards for something you've already done, or as mental preparation for what you'll do next.
In other words, "doing" does not require filling very moment of your life with busyness. Or business. Quite the contrary. Because when your life is nothing but "doing," you are losing time for thought on reflection. Similarly, "something" does not have to be something that earns money, or accomplishes a goal, or ticks an item off your bucket list.
This is what I've learned after starting to build my own business. Non-billable time is not wasted time. Projects that don't pay anything, or that don't pay much, are important. All the other things I have in my life–family, reading, music, memoir–are part of the work I do that one day will be profitable, if not self-sustaining.
Courtney Barnett's first full-length album is called Sometimes I Sit and Think and Sometimes I Just Sit. Like all of her songs, there is wisdom in that. Just sitting can be doing something. As long as it's not all that you do.