Bṛhadāraṇyakopaniṣad, without a doubt. not for the faint of heart or the ignorant.

Torn between

It's a poem published in 1979 by the son of a physics Nobel prize winner, and it's about consciousness and artificial intelligence, and how they relate to mathematical proofs, music compositions (especially Baroque organ music) and visual art. It is full of self-references.

It's a twelve-episode science mystery called "TAOCP"... eagerly awaiting episode 4c! It's full of passion, hard facts, proofs, code fragments, even music scores and of course jokes.

- Lost Connections by Johann Hari (Life, Overcome depression) - 1946: The Making of the Modern World : Sebestyen, Victor (History, WWII) - Sapiens: A Brief History of Humankind

Middlemarch by George Eliot. Well worth a read, possibly the greatest English novel ever written.

Books: Siddartha: to think about myself and my changes/voyage through life.

  Half-time: to think what-the-hell-comes-next (only if you are 40+)(it won't resonate with a 20yo)

  Systemantics, Nexus: if you work in mega-big-corpos this will save your life

  Hold on to your kids, The anxious generation: if you got kids

  Strong Fathers Strong Daughters: (and mothers/sons) if you got kids (too Christian-y for my taste but an amazing 'manual' to manage the relationship with your kid(s))

  1984, Animal Farm, Gulag Archipelago: ...

  Light on Yoga: (also do practice yoga, it's good for most-if-not-all)

You asked for "one book"... but.. life.. is not 'one' thing. Systemantics (and Dilbert) have helped me stay afloat at work. Siddartha gave me a perspective in live about myself, the different 'people' I have been throughout my life.

All the listed ones are books I read and read again every few years. They shaped me the first time I read them, keep me 'grounded'/taking stock/thinking the 'change' in me and my life. I see them as a 'check-diff' and how I have changed/evolved/devolved since the last time I read it/them.

Made to Stick by Chip and Dan Heath (its about why some ideas stick and other dies)

Tracers in the Dark: The Global Hunt for the Crime Lords of Cryptocurrency by Andy Greenberg was exceptionally well researched and told.

"The Baron in the Trees" by Italo Calvino.

It's a self-help book called Secrets of Divine Love. It helped me with clearing out so much in my life that I used to worry about. It is a slow read; otherwise, one gets bored other than that, I enjoyed each and every bit of it.

1632 by Eric Flint - It's an alternative history in which the real town of Mannington, Virginia is fictionalized as "Grantville" and thrown back in time to 1631 Germany, causing it's citizens to band together, and kick off the American Revolution more than a Century Early.

It's a fascinating study of society and the infrastructure that makes civilization work. Their struggles to avoid starvation and being over-run by the armies of the 30 years war are gripping reading.

It was so popular it spawned a community of writers and a series that lived until the authors demise a few years ago.

Barbarian Days: A Surfing Life by William Finnegan

No better way to be reminded there is a big difference between someone that surfs for fun and someone who is a surfer.

Surfing parts aside, this book taught me to appreciate the different parts of your life around your 'obsession' as you get older.

Project Hail Mary, I laughed out loud and mocked the premise of the book but it was a great read, one of my best reads ever. Very well done.

Killer of Men by Christian Cameron

Helped me reboot in my early 30s, fantastic series.

The most impactful for me was Your Money or Your Life by Vicki Robin and Joe Dominguez. Made me have a more direct association of time and money and made me focus on the fact free time is more valuable than money (to me) beyond a pretty minimal point.

Read it at 18 while working at a hardware store. Probably the best thing that could've happened to me.

Hard to choose for myself who made the post.

But some of my favorites are -

1. God: The Failed Hypothesis Book by Victor J. Stenger

2. The God Delusion Book by Richard Dawkins

3. Berlin: The Downfall 1945 Book by Antony Beevor

4. A Song of Ice and Fire Novel series by George R.R. Martin

5. A Short History of Nearly Everything Book by Bill Bryson

6. Billions and Billions Book by Carl Sagan

7. Flowers for Algernon Short story by Daniel Keyes

8. I'm Glad My Mom Died Book by Jennette McCurdy

9. Manhunt: The Ten-Year Search for Bin Laden--from 9/11 to Abbottabad Book by Peter Bergen

10. Pale Blue Dot: A Vision of the Human Future in Space Book by Carl Sagan

11. The Metamorphosis Novella by Franz Kafka

12. The Selfish Gene Book by Richard Dawkins

Gun to my head, pick one? The God Delusion.

William Gass - The Tunnel. For the past year or so I have been trying to come up with a good way to help people understand it without explaining it all away. Think I have mostly figured out how to do it, just need to spend a month or two heavily annotating the book and taking notes, and then make a website. So many books these days have terrible online resources that do more damage than good, indices and annotations which seem to index and annotate by whim with no sense of scope or purpose. Quite a few seem like they were personal projects in the creators process of understanding the novel and while I think it is great they shared it all with the world, I wish they had used what it taught them to edit their indices and annotations before they uploaded them.

Been dragging my feet on this since I don't really feel like learning all the web stuff, have not made a webpage in 20 years. Eventually I will get to it, or maybe I will find an accomplice.