This document interprets a 2023 book titled "How Big Things Get Done" by Bent Flyvbjerg, an Oxford University professor and Danish economist. The book, based on a database of over 16,000 "super projects" like skyscrapers and Olympic Games, reveals an "Iron Law of Megaprojects": 99.5% of large-scale endeavors face budget overruns, time delays, and underperformance. To counter this, the book advocates a "think slow, act fast" approach, emphasizing thorough planning (thinking slow) before expeditious execution (acting fast). Effective slow thinking involves clearly defining the project's purpose ("starting from why") and iteratively refining ideas through testing. Fast action is achieved by breaking down large projects into smaller, manageable blocks, leveraging existing successful models rather than seeking to be first, and recognizing that individual projects often conform to general patterns, avoiding the "inside view" bias.