[sulam]

While everything else you say may be true, I take issue with efficiency being a function of age. Fundamentally you have no idea how many years you will get. Be efficient at all ages, and live like it might (and might not!) be your last year, regardless. Personally I’ve had close brushes with death a couple times in my life, and the dice roll could easily have gone the other way. I’m sure I’m far from alone in this.

[BeetleB]

I did not mean to imply one shouldn't be efficient at all ages - just that those doing their PhDs in their 20s do not value it as much as those in their 50s.

Also, those in their 20s often haven't lived long enough to know how to gauge their efficiency. The person who has spent decades working 40 hour/week jobs knows better the value of less free time.