Quanta Magazine has a profile of Princeton mathematician and Fields Medalist June Huh, who “does about three hours of focused work” per day— a number in line with those of many creatives I wrote about in REST:

On any given day, Huh does about three hours of focused work. He might think about a math problem, or prepare to lecture a classroom of students, or schedule doctor’s appointments for his two sons. “Then I’m exhausted,” he said. “Doing something that’s valuable, meaningful, creative” — or a task that he doesn’t particularly want to do, like scheduling those appointments — “takes away a lot of your energy.”

To hear him tell it, he doesn’t usually have much control over what he decides to focus on in those three hours. For a few months in the spring of 2019, all he did was read. He felt an urge to revisit books he’d first encountered when he was younger — including Meditations by the Roman emperor Marcus Aurelius and several novels by the German author Hermann Hesse — so that’s what he did. “Which means I didn’t do any work,” Huh said. “So that’s kind of a problem.” (He’s since made peace with this constraint, though. “I used to try to resist … but I finally learned to give up to those temptations.” As a consequence, “I became better and better at ignoring deadlines.”)

(Via Cal Newport’s most recent newsletter.)