Maybe I should have read the book description and summary better, but I skipped the later half of the book almost entirely.
The first half is all about Patterns. And you do learn it. Each pattern is well explained, with code examples, and Addy starts with the simple patterns and build upon it, getting more complex, but you can follow along.
Then, suddenly, the book shifts from explaining each pattern to describing how several libraries, specially jQuery and Backbone, implement (in detail) some patterns. And you learn some patterns now for plugins of jQuery, in even more details.
Since I was not interested in how jQuery plugins do something, I just enjoyed half of the book.