> I'm about to hop on a 13 hour flight

If you need answers fast, the HN search feature lists hundreds of answers for "ask hn favorite book', 'ask hn best book' on multiple topics, fiction and non-fiction.

I quite liked the 'Ask HN: What books changed the way you think about almost everything?' https://news.ycombinator.com/item?id=19087418

Personally I added the audio book 'Salt: A World History' for my next long flight.

I have a rule of thumb. From a stress rating of 0-10, your days should ideally be 8 stress or 0.

Growth = stress + rest

The more elite people can take on a lot more stress. 0 doesn't necessarily mean watching Netflix; for me that's more stressful than playing with spreadsheets or commenting on HN.

What most people do is stick around 3-5 stress level (the comfort zone) or constantly at 6 (trying my best). It's a recipe for mediocrity as you never push yourself hard enough to improve.

If you've had a slow day at work, then push yourself. If you're not sure what to do, pick up a book. Something like this is nice to start: https://news.ycombinator.com/item?id=19087418

You can practice typing faster. Learn keyboard shortcuts; they're probably the biggest leverage I have in programming now. Learn speed reading or how to get to 90% comprehension. These are all fun things to do, yet enough to tire you out.

But don't do this every night. Find things that actually replenish you, not some mindless semi-productive activity. I personally love playing with my kids, watching superhero movies, reading web fiction or TV tropes, or idle games that involve wikis and spreadsheets. You find your thing.

I good judge is how I feel in the morning. If I'm physically or mentally sore, I need to focus on rest that day. If I can naturally wake before 6, it's a day to push myself.