https://en.wikipedia.org/wiki/The_Illuminatus!_Trilogy
More recently I've been reading through Antifragile: Things that Gain From Disorder by Nassim Taleb, and while I'm not completely on board with everything he said (his assertions that academia contributed virtually nothing to the development of the computer rang particularly false to me, so some of his other assertions are similarly suspect), it is forcing me to think of how I can live my life in a way that is less susceptible to things outside of my control.
For example, I've been following cryptocurrencies quite a bit and have some 'skin in the game' there, and that field does seem to require some 'antifragile' thinking in order to weather its volatility.
The book seems to be particularly good if you want to get more into the entrepreneurial or creative mindset.
Now I am really impressed by the Culture serie [1]
It's a lot about finding purpose in life.
I started reading his stuff and then I became angry at him and at me.
At him because he showed me that I'm a slave of nature and at me because I started questioning life and humanity.
Then I started to disprove his thesis and found my own purpose in life, not only that, it also gave me a much better understanding of human nature, which can be used in marketing or product design.
I would actually just recommend a book that does a summary of all his books, that's enough in my opinion.
His stuff is very hard to read and I often had to ask professionals who then translated or explained it to me.
Though you're probably good just skimming over anything he had to say about women or non-white people :p
Even my 19th-century edition of his essays comes with a prefatory warning.
https://en.wikipedia.org/wiki/How_to_Win_Friends_and_Influen...
https://en.m.wikipedia.org/wiki/The_Hero_with_a_Thousand_Fac...
- [0] https://www.robinwieruch.de/lessons-learned-give-and-take/
It helped me quit smoking and run 2 marathons.