What is the most powerful tip you’ve gained from reading a self-help book?

Answer by David Throop:

The Most Powerful Tip I've Discovered From Self-Help Books
In a recent blog post, I discussed this point specifically.  You can read the entire post here: The ONE Thing You Can Do To Improve Your Productivity – an article that is both a book review and a personal discussion of application.
In summary, the most powerful tip I've discovered is to focus on just ONE thing.  In their book "The ONE Thing" by Gary Keller and Jay Papasan, they discuss the power of focus and motivation through simplification. 
Who are Gary Keller and Jay Papasan? Gary Keller is founder of Keller Williams Realty, the number one Real Estate company in the world.  He built the company in his lifetime using many of the tactics and techniques he discloses. 

Jay Papasan is the Vice President of Keller Williams on the PR side, focusing on speaking engagements and writing.

Some of the reader comments talk about how the book is a resource to help you maximize your productivity by developing simple, straight forward tactics.
"Keller believes in focus, utter dedication to your one thing, and driving to breakthrough barriers to get to your one big purpose"
"Simple, yet effective way to see beyond the tyranny of the urgent and focus your efforts on the important."
The authors also discuss the big myths associated in contemporary society such as:
1. Everything Matters Equally
2. Multitasking is Good
3. Success Requires a Disciplined Life
4. Willpower is Always on Will-Call
5. A Balanced Life is Required
6. Big is Bad
In essence, the key to achievement is focusing on a single goal and being driven to see it through to completion.  The tactics help teach was to overcome potential hurdles by the simplification of their strategy.  
You can get a copy of The ONE Thing on Amazon for Kindle or Print copy through this affiliate link HERE: The Surprisingly Simple Truth Behind Extraordinary Results: Gary Keller, Jay Papasan: 9781885167774: Amazon.com: Books

What is the most powerful tip you've gained from reading a self-help book?