In order to be in business for yourself you have to be passionate about what you do. In the first few years of a new business chances are you are going to be losing money and not making money. If you are losing money how can you continue to put in long hours of work and investment everyday?
The only way you can continue is if you are not in it for the money. I am a stern believer in following your dreams. I like to dream. Its really all we have. Couple those dreams with some actions and you never know what might happen.