I started making monkey bridges, like kids do, and climbing and rappelling with ropes. Very naturally, I needed some knots. At the very beginning, I didn't care, I didn't know, and then slowly I started to know, and I started to care. I wanted to know more knots or the right knot for the special action.
Notre Dame and Sydney - that was nothing. Notre Dame doesn't have a police station; it is not 1,000 or so feet high. It was a public structure, very easy to access. And Sydney Harbour Bridge was half-and-half: a bridge, in the middle of the night. The World Trade Center was the end of the world. Electronic devices, police dogs.