I agree with this in general, but if you’ve already done some Google sleuthing (as mentioned in 7.), found those curated lists, looked at reviews, and you still don’t enjoy a book after such heavy self-selection — should you put it down? Is that saving time or is that refusing to leave your comfort zone?
The question is what is enjoyment.
If you’re reading for mindless entertainment, then reading should be mindless or fun or funny or …
Rubin defines enjoyment as getting valuable information.
I decided to set myself a new habit: Stop reading a book if I don’t enjoy it. (I consider getting valuable information from a book as a form of “enjoyment,” even if I don’t particularly enjoy the experience of reading it.)
How do we determine what valuable information is, if it’s not factual? (Say, if it’s fiction.) In that case it does come down to the experience of reading (or else, the iron will not to stop).
Often a book that is a grind at the beginning has a point, eventually. Be that to hone your tastes further (and therefore improve your self-selection criterion), to teach you a lesson you’ve been refusing to learn (opinion inbreeding is a disadvantage of self-selective reading), expand your horizons philosophically, emotionally, ethically, etc.
I fully support dropping some books because life gets in the way or because they’re utterly impenetrable or because there’s a pressing need to read more relevant books (due to job, family, illness-related issues, for example), but by no means would I recommend dropping every book that isn’t enjoyabe in the first few chapters. Especially if you chose it from a good source and for a good reason.
A modicum of randomness keeps opinion inbreeding away. After all, reading is meant to open the mind; don’t shut those books too quickly.