The Dalai Lama’s Book of Wisdom[0] includes a page on the practice of considering each day a number of ways (eight, here) a person might die, towards dying with more grace when the time comes. I started practicing and found it an engaging creative exercise. It’s also helped me take better care of other living things, and to see non-human animals as people, too. I’m still part of numerous kill-chains (weeding the garden, turning the compost, walking, using electricity, eating plants and animals, paying U.S. taxes and benefiting from the infrastructure, and so many more), and I accept that as part of living.
[0] https://www.worldcat.org/title/dalai-lamas-book-of-wisdom/oc...
"The Death of Ivan Ilyich" by Leo Tolstoy: https://en.wikipedia.org/wiki/The_Death_of_Ivan_Ilyich
Also, +1 for Jiddu Krishnamurti.
nearing the end of their life professors tend give one last lecture reflecting their life lessons. most people don't know it's their literal last lecture, but Randy was diagnosed with terminal cancer at 40s and he is an interesting guy I wish I could've met.
another one stretches slightly over 100 is The Brain That Changes Itself.
Tom Crewe wrote of ‘The Strange Death of Municipal England’ on 15 June 2016 (https://www.lrb.co.uk/the-paper/v38/n24/tom-crewe/the-strang...). I suppose that at the time I was broadly a utilitarian and had very évolué/neoliberal politics. This exposed something of a tension between them and I ended up at a rather different place politically. I suppose that I am rather a slave to, if not passions, pangs of guilt, and so occasionally a day or two will be upended in (often useless) politicking of one sort or another—a moderately important feature of my life. The other article that had some effect was Mahmood Mamdani’s ‘The Invention of the Indigène’ (https://www.lrb.co.uk/the-paper/v33/n02/mahmood-mamdani/the-...).
The second effect, I suppose, was to broadly influence my intellectual outlook: first, in a rather uncritically admiring sort of way, and then, beginning with the observation that the book reviews never mentioned the books, more critically: untranslated French is a good reminder that I ought to read French newspapers more often, but when will the historians be reminded e.g. to understand elementary probability? Useless chattering is an excellent pastime however, and the LRB was terribly good fodder.
[1]: https://www.goodreads.com/book/show/35528537-the-goal
[2]: https://www.goodreads.com/book/show/157993.The_Little_Prince
1. Fear, Thich Nhat Hanh, helps you cope with anything
2. The Stranger, Camus, Nihilism/Stoicism
3. The old man and the sea, Hemmingway
It’s quite old and maybe overplayed but I enjoy THE ART OF MONEY GETTING or GOLDEN RULES FOR MAKING MONEY By P.T. Barnum. His insights might be about 200 years old, but they are in the exact same vein, and perhaps a bit more tasteful language.
Letters to a Young Contrarian - Christopher Hitchens
The Old Man and the Sea - Hemmingway
Both gave me an appreciation of the writers that led me to read more of their work which ultimately made changes in my life. With Hitchens his work on religion had a profound impact on my world view, with Hemmingway it gave me an appreciation for good writing and story.
Showed me the easy way to stop smoking. (Not 100% sure if it's under 100 pages but at least not much more)
Best bang for the buck for people in early 20s
If you want to read something of substance, read. There are no shortcuts.
War and Peace is 12-13 "short" books.
Letters to a Young Poet
Letters from a Self Made Merchant to His Son
Sections of Meditations
Sections of Seneca
Bed of Procrustes
And also 'Instant Zen' by Foyan (136 pages).