There is a rule of thumb which says “Whatever got you to where you are today is not enough to get you any further.” What this means is that your current level of knowledge and skill has been sufficient to achieve your current income and standard of living. But in order for you to improve, to move onward and upward, you must learn and apply new skills essential for professional and personal growth. And there is no other way to get ahead except to become better at what you do.

There’s another rule which says “For life to get better, you must get better.” The good news is that there are no limits to how much better you can become. Therefore, there are no limits to how much more you can change your life, if you have the determination and the discipline to do so. Everyday in every way you should be looking for ways to change your life and increase your personal growth.

Change your life. The first step in your growth is to resolve to get into the top 10 percent of your field. The way to do this is both simple and powerful. What we have found is that, in any profession, there are never more than five to seven key results areas. These are the skills you absolutely, positively must have in order to do your job in an excellent fashion.

Here is the breakthrough discovery: The skill area where you are weakest sets the maximum height you can achieve. You can be excellent in a variety of areas, but it’s the one essential area where you are weakest that determines how far and how fast you will move. What this means is that improving in your weakest area will allow you to move ahead faster than any other activity you could pursue.

Here then is the key question: “What one skill, if you were absolutely excellent at it, would help you the most to move ahead more rapidly in your career?”

There are no limits to how much you can improve. Now make a list of all the things you could do to master this skill. List the books you could read, the courses you could take and the people whose advice you could seek. Most important, list the specific activities you could engage in every single day to learn and master this skill, and then get busy doing it.

Every skill is learnable. Here’s the best news of all: Every sales skills is learnable. Every money-making skill is learnable. Everyone who is good at a skill was at one time incapable of doing it at all. And what hundreds of thousands of other people have done, starting at the bottom, you can do as well, if you have the necessary discipline and determination.

Remember, there are no limits to how much better you can become, if you have the discipline to start and the determination to continue.

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Brian Tracy is the CEO of Brian Tracy International, which specializes in business training, and the author of the best-selling Psychology of Achievement. For more information, go to www.briantracy.com.