I believe them. I remember calculating the optimal amount to work, to maximize non-work non-sleep healthy life expectancy, and it was somewhere around 2 hours

I believe them. I remember calculating the optimal amount to work, to maximize non-work non-sleep healthy life expectancy, and it was somewhere around 2 hours per day in my case. Accounting for retirement, it'd be around 4 hours. If you work more than optimal, you lose free time.