The third enemy inside is doubt. Sure, there's room for healthy skepticism. You can't believe everything. But you also can't let doubt take over. Many people doubt the past, doubt the future, doubt each other, doubt the government, doubt the possibilities and doubt the opportunities. Worse of all, they doubt themselves. I'm telling you, doubt will destroy your life and your chances of success. It will empty both your bank account and your heart. Doubt is an enemy. Go after it. Get rid of it. The fourth enemy within is worry. We've all got to worry some. Just don't let conquer you. Instead, let it alarm you. Worry can be useful. If you step off the curb in New York City and a taxi is coming, you've got to worry. But you can't let worry loose like a mad dog that drives you into a small corner. Here's what you've got to do with your worries: drive them into a small corner. Whatever is out to get you, you've got to get it.