It's hard work making movies. It's  like being a doctor: you work long hours, very hard hours, and it's  emotional, tense work. If you don't really love it, then it ain't worth  it. 

 George Lucas 

“You see things; and you say, ‘Why?’ But I dream things that never were; and I say, ‘Why not’?”

– George Bernard Shaw

I dream for a living. Once a month the sky falls on my head, I come to, and I see another movie I want to make.
Steven Spielberg