Often times in life we become disappointed. Its true, at least once or twice in your life you will be disappointed. Most people will tell you to count your blessings, look on the bright side of things, etc... but you will not get that advice from us. The key to avoiding disappointment in life is to lower your expectations. This advice is good for life as well as being successful at business.
If you are expecting to start a business and make millions of dollars right away... your expectations are too high. You should lower your expectations. Instead of expecting to make a million dollars, you should strive to not lose a million dollars! That way you will never be disappointed (unless you loose a million dollars of course).
Lower your expectations and you will be successful!