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).
I think approaching your work from the standpoint of "Learn
from success, not failure" is a sure path to succumbing to
confirmation bias and becoming a one-trick pony.
And the stats mentioned show, that approaching work from standpoint "learn from failure" is a sure path to being zero-trick pony. The stats in question show, that those who failed previously have the same success rate as those who never even tried, and those who succeeded previously have success rate higher by third.