What books should every athlete, aspiring leader, entrepeneur, thinker and doer read?

[Ameshairos]

Saw a quote in the "Praise" part of Ryan Holidays book "Ego is the Enemy", where George Raveling says that every athlete, aspiring leader, entrepeneur, thinker and doer should read it.
Good. Quite an interesting basis to search for. Isn't it?

I'm reading "The book of not knowing" for now, which should also added to a general "must read" list, since it literally changes how you see the world.
But, that's it for me. Haven't read that much and also got not much time to do so.
So I'm asking you now:

What are your must read books and why?