`Why We Sleep: Unlocking the Power of Sleep and Dreams` by Matthew Walker. Still in the midst of it actually, and it's had a huge impact. Runner-up would be `the end of religion` by Bruxy Cavey.
Also recommended in this reply
Typographic jacket · original cover not fetched
FROM THE SHARED SHELF · 2006–2026 SAMPLE
Topics are model-inferred labels.
THE WORD OF MOUTH
Original Hacker News comments, in the readers’ own words.