I love my work, apart from when it's driving me crazy. But I get to be interested in stuff and think like a filmmaker as I'm buzzing about the world and then see an opportunity to make a film, and then make it happen.

I can't help seeing 'Waste Land' as the third in a triptych with my earlier films 'Devil's Playground' and 'Blindsight,' and not least in the awe and gratitude I feel for the group of people who were courageous enough to share their stories with us - and to live lives so rich in inspiration for us all.

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 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.

Extreme sports tricks are becoming increasingly complex, the courses ever more challenging and crashes all too common.

I love my work, apart from when it's driving me crazy. But I get to be interested in stuff and think like a filmmaker as I'm buzzing about the world and then see an opportunity to make a film, and then make it happen.

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.