In my experience, the people that follow their hearts and succeed financially are born wealthy. They go to college, which is fully paid for my parents, and major in art, photography, film, dance, theatre, etc. After college, their parents either give them a large chunk of money, die and leave them everything, or just send them a check every month. The parents facilitate their child not having to go out and get a job of any kind, so they can spend several years working on their paintings, screenplays, novel, or travel the world taking photos. Keep in mind, their friends are all usually wealthy and well connected as well. After a few years of uninterrupted dedication, a screenplay will be sold, a novel published, or a photo bought. The actual money they live off is family, or unearned money, but they have created the illusion that they are a successful artist or writer because they work all the time on their goal and have a nice living. Max Landis, Megan Ellison, Lena Dunham, and many more people in the film industry come from this kind of background.
The regular people without wealth usually have much more practical "dreams". For instance, to open their own hair salon, or leave their job at the post office to be a personal trainer, or to open their own auto shop. Their dreams are mostly about being their own boss and getting out from under the thumbs of other people. These people work very very hard, often with full time jobs and families and dedicate every ounce of strength into achieving their goals. Loans, saving, and small investments from friends might help, but can't be counted on.
About 40 years ago and before, it was easier to succeed. Now, if you are a regular Joe, you must put in triple the effort of any rich person to be recognized for your talents.
If you are under 25, have no kids, and no serious debt, you are in a fantastic position to follow your dreams. Even if you want to be an artist or a filmmaker. You can do it. Want to be a video game designer? Go to school for it. For those of us who are older, more tired, with debt, shit jobs, obligations...we can take fewer risks and dreams need to be more realistic.
For instance, a friend of mine just opened his own tattoo shop after 20 years of being an artist for someone else. I am sure when he was 19 he was hoping his band would take off and he would be a rock star. That never happened. He knows he will never be rich, never be famous, never be powerful, but he is content to work for himself in a field he enjoys and is good at.
Dreams change. What is possible at 20 can be impossible at 45.