Hacking Life by Joseph Readle is a really good read and should be one of those non-finance books FIRE folks should get their hands on. I liked it so much after borrowing from the library, I bought a Kindle version for reference. The book is really a no-holds-barred work that spills the beans on modern-day gurus.
One underlying theme in the book is the notion of over-optimising something at the expense of the big picture, I will share two particular examples that I enjoyed reading very much.
The first example is Seth Roberts who experimented on himself with butter. He figured out that 60g of butter improved the speed by which he solved simple maths problems from 650 ms to 620 ms. This enabled him to publish a book called The Shangri-La Diet. Well-meaning cardiologists have been telling him that he’s killing himself with the kind of diet he is putting himself up with.