Books about Reality?

I would like to read a book that addresses philosophically (but not just theoretically) about reality, in the sense of existence. About the universe, but not the planets, space and those things… the UNIVERSE, Everything, Reality, you know? In the sense of consciousness and what life is…

Preferably they are not religious, do not tell stories (like Sapiens – A brief history of humanity, it has nothing to do with what I’m talking about), nor are they pseudoscientific.

by rdalves