It depends a lot what you want to focus on in life, if money is important and you want to build that nest egg, it may be worth going through the leetcode grind.
(tiny self promo, I built spacedleets.com which is a site that uses spaced repetition when you are doing leetcode prep, its free and hopefully will make the leetcode grind a lil less stressful :)
Some of the books on my list are:
The Secret Life of Salvador Dalí
Doctor Goebbels: His Life and Death
I, Claudius by Robert Graves
The Agony and the Ecstasy
Lust for Life
Carl Jung Memories, Dreams and Reflections.
Stephen King - On Writing
1) Find what people are already paying for (on Fiverr/Upwork) 2) Build a product that solves that problem
Use https://insanelygood.tools/problems for free market research