I'm not sure what "fundamentally" means in this context, but these certainly made a lasting impact upon my young mind: Godel, Escher, Bach by Douglas Hofstadte

I'm not sure what "fundamentally" means in this context, but these certainly made a lasting impact upon my young mind: Godel, Escher, Bach by Douglas Hofstadter Dune by Frank Herbert Post Office by Charles Bukowski V. by Thomas Pynchon Blood Meridian by Cormac McCarthy Pretty much everything by JL Borges