One day you awoke understanding you were experiencing reality. You have some limited window from your internal world through which you may peer out into the universe. You’ve been watching a movie in which you’re clearly the main character. A central challenge for self-aware beings is really grokking just how wrong that perception is.
Your sense experiences have access to such a small a part of the universe—both spatially and temporally. Your notion that you are an indivisible being in conscious control of your inner life is utterly incorrect. You are rather a collection of trillions of cells, many of which are bacterial, and the very notion of you as an individual is an incredibly complex emergent phenomenon. Furthermore, ingesting some tiny amount of various chemicals can entirely change your conscious experience, from correcting some biological deficit so your brain better matches that of a healthy individual, to causing you to perceive things which are not present or even temporarily erasing your consciousness entirely (recall the unassuming term ‘general anaesthesia’).
Nor are humans some monolithic, qualitatively different sort of life set apart from the rest of the natural world. Our embryological development betrays our shared roots with animals which end up looking quite different from us, not to mention of course the humongous genetic similarities. As part of the naturally-occuring genetic variation among humans, people have qualitatively different inner lives. Some people have an inner monologue, while others don’t. Some can visualize things in their mind, while others cannot. There’s no one ‘human experience’ even ignoring all external circumstances.
And nor is the Earth we know now reflective of how it has been for most of its history. Life has radically altered the evolution of the Earth many times over. For many hundreds of millons of years the early Earth atmosphere was devoid of oxygen until early single-cell organisms poisoned the atmosphere with it. Dirt is wholly a biological product. There was a period millions of years long after plants developed woody structures when no microorganisms could digest them, and dead trees built up in thick layers. The biosphere extends from the upper reaches of the atmosphere where microbes feed on dust, down through the very depths of the deepest holes we have yet been able to dig where microbes digest abiotic resources in hairline fractures in rocks.
This is a starkly different picture of life and of the universe than anyone had before the scientific revolution. Not only is this an absolutely amazing amount of progress for us to have made in just a few hundred years, but—to me, at least—this serves as reason to be skeptical of worldviews from such times.