Where X is as small as possible, and seek to cull it further by combining equivalents and trying to identify why some 'important' things might actually be utter wastes of time in the first place.
The world generally uses a ratchet approach to conquer your attention. Use a ratchet to take it back.
Recently, I've started to adopt a similar perspective by rigorously evaluating everything with a simple question: "20 years from now, will my kids be proud that I did this?" If the answer is no, I stop it. So far, I've stopped playing video games and using social media, and I've noticed that I've gotten an extra 10-15 hours per week to spend on things that will make me a better person in the long term, like reading, working out, and spending time with my friends and family.
The same approach could be used with any endeavor: "In X years, will I be better at <subject> if I continue to do Y?"
Delegating social media and other trivial pursuits to family and friends can free up an additional 10-15 hours per week for HN! :)
More seriously, to get the most out of HN:
1) skip the aviation and database threads and just read my posts. (There are very few qualified commenters on those topics.)
2) for other topics, read a few posts and if it looks interesting, find an in-depth article or blog on that topic.
They can and should be replaced by more effective forms of rest (meditation, sleep, walking, etc) but intellectual work just isn't happening in that state. Or if it does, it leads to a harder crash later.
I have to roll my eyes a little at the "produce X% more by working through your breaks" thing. If you can do that sustainably, why were you taking breaks to begin with?
I don’t meditate, I let my mind wander and don’t judge anything. The only rule is I’m not allowed to physically move, I find a comfortable position and must remain in that position for 10 minutes.
It’s excruciating at first, but about 5 minutes in my mind has processes whatever it had stored up and I’m tired. About 8 minutes in I’m shutting my eyes. Sometimes I have to give and just go to bed.
FWIW, that description seems compatible with meditation technique. Meditation can be non judgmental in that way, and just be a matter of experiencing the state of your mind.
― Douglas Adams, The Hitchhiker's Guide to the Galaxy
Before you recoil in disgust, let me note that I have read many many books and love reading. I value literature a lot but when it comes down to what I do in life and what things REALLY REALLY give me in the end, then books don't perform better than a range of selected video games (to my own gusto). In then end, a book doesn't propel to new positions more than a game does, unless it'sa book meant to teach me new technology or so.
It's simply another form of media, another form of story telling and conveying experiences. And while I enjoyed "Marc Aurel's Meditations" and took a lot of benefit out of it, Persona 5 also provided me with some good, memorable experiences that make me rethink life. Even just the "Take your time" loading screen spinner... If I put them on a scale it's simply even for me in value.
You should consider playing "Tales of Berseria". It poses an interesting question: "Why do bird fly?", and gives interesting answers.
Or be an Epicurean and enjoy the neutral state most, pleasures but not at the expense of pain.
Or be a Stoic and find comfort in realizing you aren't invading Russia in the winter.