From Time Tactics of Very Successful People:
Don’t confuse busyness with efficiency. An organization’s best people sometimes spend their most productive time seemingly daydreaming.
Busyness may, in fact, be counterproductive. “It is necessary to be slightly underemployed if you are to do something significant,” says James D. Watson. He is a Nobel laureate who shared the prize with Francis Crick for successfully discovering the genetic code of DNA. The story of how underemployed they were — the stories of their meanderings and long weekends, parties, visits, and other diversions — is told delightfully in The Double Helix: A Personal Account of the Discovery of the Structure of DNA, a human-side-of-science classic.
Watson and Crick had the luxury of being able to study all sorts of ideas, interact with scientists in many fields, attend conferences all over the world. But most of all, Watson and Crick had time to think about what they were reading and hearing and seeing. That’s what Watson means when he praises underemployment.
If these two researchers had not received generous research grants, if they had needed to hold down two jobs in order to make ends meet, they probably would not have made the discovery that revolutionized biological research. Thanks to generous support plus the British university tradition that emphasizes contemplation, Watson and Crick were sufficiently underemployed to do something significant.
People on treadmills don’t get very far [emphasis added]. If you’re so busy working that you have no time to think about what you’re working at, you’ll be unable to make full use of your accomplishments.
Underemployment provides the time between activities to reflect on what you’ve just finished and think, “What does this mean?” “How can I exploit what I have done?” Underemployment provides the time to figure out other ways than the obvious to use what you’re producing. And it provides time to consider how what you’ve done fits with what’s already been done.