To the person doing it, it feels closer to arithmetic. Finishing a book you aren’t enjoying, purely so you can say you finished it, is extrinsic motivation at its purest. A bad book isn’t just a bad book. But on a Saturday afternoon, alone with a book that isn’t working, the reflex has nowhere to hide. The quiet partPeople who can finally put down a book they aren’t enjoying are not, mostly, people who have gotten worse at commitment.