I remember growing up playing the piano, thinking how easy it was for me, and contemplating fame and riches as a rock star. :-) I picked up music without any real effort, so when I was around 19 decided to go professional.
One of the key things to remember is that whatever it is you really like now, where there`s no pressure, that`s going to be whatever you`re doing every single day if you make it a business. It won`t matter if your tired, depressed, or you have a 104-degree temperature and the flu; you`re still responsible for getting work done.
I remember being on stage, so sick I couldn`t even see straight, but with a contractual obligation to play. AND to make it look like I was partying and having a helluva time. There came a time when I left the music business, and couldn`t care less if I ever saw another piano.
It`s true that having a business organized around your passion is likely the better way to go in life. For a long time, you`ll probably find that you don`t "feel" like you`re working. Instead, you`ll be doing what you love to do. The problem is that in most cases, doing that same thing for 30 years really does get old, y`know?
So my suggestion would be to examine your life and come up with a sort of general plan. Perhaps you`ll start a poker business, but there`s no law that says you have to keep running it for 30 years. Instead, you could figure out a way to not only start the business, but also your "exit strategy."
In other words, decide that you`ll build and run a business, but only for 5 years. At the end of that time you`ll have created a situation where you can choose either to continue for some more years, or sell it or close it down and do something different. The point being choice.
Think of your business as a marriage. Have you been dreaming of being married since you were 12?
When you DO get married, how long do you think you`ll be married?