In his book, The Common Denominator of Success, Gray says a common denominator is “a feature shared by all members of a group.”The common denominator of success – the secret of every person who has ever been successful – lies in the fact that he or she formed the habit of doing things that failures don’t like to do.It will still explain why many come into business with every apparent qualification for success and give us the most disappointing failures, while others come in and achieve outstanding success in spite of many obvious and discouraging handicaps.By doing the things they don’t like to do, they can accomplish the things they want to accomplish.When a person goes into a slump, it simply means that he has reached a point at which, for the time being, the things he doesn’t like to do have become more important than his reasons for doing them. The less you talk about production and more you talk about purpose the better.Isn’t making a living a strong enough purpose? No, it isn’t. It isn’t sufficiently strong to make you form the habit of doing the things you don’t like to do for the very simple reasons that it is easier to adjust ourselves to the hardships of a poor living than it is to adjust ourselves to the hardships of making a better one.Unless you have formed the habit of calling on people who are able to buy but unwilling to listen, then unconsciously you have formed the habit of calling on people who are willing to listen but unable to buy. Any resolution or decision you make is simply a promise to yourself, which isn’t worth a thing unless you have formed a habit of making it and keeping it. And you won’t form then habit of keeping it unless right at the start you link it with a definite purpose.