His key ideas are easy to follow because he keeps it simple and Scott Adams writes in a clear and witty manner
For example the chapter on applying a system vs setting goals and trying to follow them was worth the price of the book many times over for me (and this is reinforced through the book). In his own words goals are a reach-it-and-be-done situation (where you are often waiting to achieve it someday in the future) whereas a system is something you do on a regular or daily basis with a reasonable expectation that doing so will get you to a better place in life. Wanting better health or wanting to lose 10 kg are goals. Being active everyday is a system. One is tied to another - but goals people are fighting the feeling of discouragement at each turn and the systems people are feeling good every-time they apply their system.
I wholeheartedly recommend this book to anyone smart and weary of reading tired cliches in the self-help genre. The book is a breath of fresh air!