The irreverent Head First style cleverly disguises the fact that you will walk away from the book understanding 'stuff'. This is not a recipe book, and it is not a code mill. The examples are for one purpose only: trick your brain into understanding a concept. The exercises do the same thing - often adding emotional spice by letting you walk straight into a trap (a typical mistake made by most novices), and then helping you understand exactly why you made that particular mistake on the very next page.
Did someone say "Just in Time" learning?