I am the greatest, I said that even before I knew I was.Muhammad Ali
If you do not think you are the best you will not take the action to get the best results. You have to think about what is possible. You have to believe. You have to take action to get the results. Anything stopping you from this is a lie. If you are not as confident as possible then you are lying to yourself. The more results you see the more you will believe in yourself and the more action you will take. You are the one in control of what you are focusing on and the action you are taking.