> hours of labor are not required for achievement? Well, you need to put in something like 3-8 hours per day, certainly. But it's been documented over and over

> hours of labor are not required for achievement? Well, you need to put in something like 3-8 hours per day, certainly. But it's been documented over and over that 60+ hours a week does not increase your productivity. Each book does contain evidence for its claims based on research. Perhaps "Deep Work" is more anecdotal than the others, but Cal is up-front about this.