Books are some really great tools for improvement but they can be easily misused. Despite the powerful information they carry, they can also be used as a how to guide which can impact the very thing you want to accomplish, which is improvement. The books should be read in order to be inspired not in order to follow a step by step process.
The biggest books we ever know are ourselves which we gained throughout our experiences on this planet. Our inner voice will always beat the book we are trying to “follow “therefore books should only be used for inspiration purposes only. Your own voice is the one which is the most qualified for you to listen to. Then inspiration can be gathered from other resources.
Working on “how to material” makes you focus on the idea that you are lacking the “x rather than you have it and you can give yourself more of it. For that reason you can be working on them for a long time and see very little improvements.