By the time he turned 30, Tim Ferriss had figured out how to succeed at things that many people fail at—from growing a business to dancing the tango to marketing a best-selling book. He approached these and numerous other challenges by breaking them down into manageable chunks, carefully documenting his own progress, and taking copious notes. That formula is now wrapped into a hugely successful personal brand that blends optimism with discipline and includes five books and a popular podcast.