The regrettable consequence of justifying leisure only in terms of its usefulness for other things is that it begins to feel vaguely like a chore—in other words, like work in the worst sense of that word.
Rest is permissible, but only for the purposes of recuperation for work, or perhaps for some other form of self-improvement.
It becomes difficult to enjoy a moment of rest for itself alone, without regard for any potential future benefits, because rest that has no instrumental value feels wasteful.
The truth, then, is that spending at least some of your leisure time “wastefully,” focused solely on the pleasure of the experience, is the only way not to waste it—to be truly at leisure, rather than covertly engaged in future-focused self-improvement.
In order to most fully inhabit the only life you ever get, you have to refrain from using every spare hour for personal growth. From this perspective, idleness isn’t merely forgivable; it’s practically an obligation.
This was taken from Oliver Burkeman’s latest book on time management for Mortals: Four Thousand Weeks.