The rest of the time, they were hiking mountains, taking naps, going on walks with friends, or just sitting and thinking. Their creativity and productivity, in other words, were not the result of endless hours of toil. Their towering creative achievements result from modest “working” hours.
If Darwin spent most of his time "hiking mountains... or just sitting and thinking", guess what he was actually doing? Yep, he was studying, and working. Just because he was not hunched over a table or a microscope does not mean he was not studying.