When aspiring photographers ask me how they can become professionals, I start with the same question, "Why do you want to be a professional photographer?"
It's not a trick question, and there's no right or wrong answer. But in my experience it's helpful to know your own motivations and why you would want to subject yourself to the agony of trying to earn a living doing something that you're passionate about, in a cut-throat, crowded field where someone else is always willing to do a job for next to nothing. What will sustain you when you're doing the bidding? Your taxes? The grunt work?
For me it's simple. I became a professional photographer to meet interesting people and find myself in unusual places. Not for the love of the art form, not to shoot women in bikinis, not for dreams of winning a Pulitzer. It's simply the selfish desire to rub elbows with and learn from fascinating people and experience places most others will never see. I work hard on the product, but I always try to enjoy the process.