I think when you're a director, it's hard to do something unless you're absolutely over-the-moon in love with it. The audience, they spend 90 minutes with it, but for you, it's anywhere between a year and a half to three years of your life, every day, working on it.
You may love football, but that doesn't mean you have any business trying to play the sport. It's the same thing with filmmaking... everybody has a great idea for a movie, but do you have the stamina to get good at your craft and deal with how heartbreaking it is?
To all the other dreamers out there, don't ever stop or let the world's negativity disenchant you or your spirit. If you surround yourself with love and the right people, anything is possible.