I'm currently reading the book, and he amusingly left out the stats supporting their conclusions or the rest of the sentence which tempers the strong advice. This is obviously intentional.

They say "Don't make plans" and end the sentence with "Before you start, you don't know anything then".

They say "learn from successes, not failures" and back it up with stats about how people who failed at a prior business endeavor are no more likely than first time starters (23% of succeeding), but people who've succeeded at prior business have a much greater chance (forgot that number).

Uneven smear job a stuckup business writer.