The book teaches various techniques and shortcuts to understand and implement this concept in our lives. Throughout the period when I was reading the book, I was unconsciously nodding my head in approval of the theories discussed, realizing how true and appropriate each one of them is.
It's basically pretty common sense, what you think about and talk about the most is what you get more of. Where the attention goes, the energy flows. If you constantly talk about being broke, or sick, or depressed, then that's what you will get. Even if you're bank account, health, or mental disposition is not currently where you'd like for it to be, you completely have the power to take one little step at a time in the right direction. No matter how adverse a sitation gets, surely there must be something that makes you happy, something that you are essentially grateful for -- Awesome friends and family, loving pets, a roof over your head, a kick ass music collection, etc.