The Parable of the Sower, by Octavia E. Butler [0], because it helped change and focus my values around extending the story of life on earth in an unbroken way thousands of years into the future, so that people can look back on history with greater understanding. I grew to accept my own death more fully, and to live it like a book rather than an endless MMORPG.

[0] https://www.worldcat.org/title/parable-of-the-sower/oclc/125...