The core message is to reduce risks that may produce tail events. The example around hiring every single archaeologist in Britain for HS2 is great, but then Flyvbjerg lacks a wider description of why HS2 is still ongoing, since it clearly has been a planning disaster (is it bat tunnels and stone-skipping bridges?). Other notes around projects which are one-of or first-of are great, but I would rather a book that explores a single project in great depth rather than jumping across examples whether they are the despair of the architect of the Sydney Opera House or a couple in Brooklyn. I did use the advice around understanding expected costs for the median project of that type to plan for my loft conversion but the part I do have expertise in: planning software projects, and seeing how Flyvbjerg treated that, made me skeptical of the remainder of the claims.