Commitment - "the vision thing." You will not accomplish your goals through mere wishing or hoping. You must make a commitment to your goals.
When others in your life hear that you are pursuing the entertainment industry they are likely to scoff or perhaps worse, try to 'talk you out of it , for your own good.'
Unless you know how to commit - without jumping off a cliff - you will face tremendous emotional turmoil.
James Cameron did not quit his day job - he drove a truck - but he worked toward his real goal - involvement in film, and ultimaltely directing. Don't quit your day job. But do commit to your passion... understand it and get experience as you are moving into a brave new world. See you at the movies!