I find titles the hardest thing. I was worried that 'Waste Land' was too much of a downer. For me, 'The Crash Reel' confronts what the film is about: it's not just about the reality of a crash, it's about the extremity we all face, and what happens when life crashes on you.

I remember when the Berlin Wall fell and suddenly intractable problems get solved.

I love great locations in movies, and I couldn't believe I'd never seen a landfill on screen before. It was the most haunting place.

I can ask someone to let me into all aspects of their life for several years, but people have got to have that gift: that courage and that talent for opening their lives to the camera. Being candid is a gift, and that's what the audience responds to. Part of it is me asking, and part of it is just their inherent talent, which is what you are looking for when you make documentaries - people that are really going to let you in on what they are going through.

I think we've reached that point where we understand medically what we are doing to ourselves with these sports. In football, it's kind of hard to get the access that you want for the story and, of course, it's very long-term: the effects of the repeat concussions really don't hit until decades afterwards, whereas the traumatic injuries in extreme sports are very immediate. I realized Traumatic Brain Injury was a fascinating and important story that not had been told very much. I wanted to know more.

I'm not an expert on how to configure the sport, but I can observe and say that accidents seem to be a part of it. The athletes are incredible, with the courage that they accept the risk of death, paralysis, and brain injury. These are really life-changing, life-threatening injuries, and the risk is extremely high.

I am riveted by extreme sports like big-wave surfing, 'megaramp' skateboarding and half pipe snowboarding. I am fascinated partly because the sports are so exhilaratingly acrobatic. But I am also captivated by the fear that a terrible accident might happen at any moment. And accidents do happen.