When you go to the mountains, you see them and you admire them. In a sense, they give you a challenge, and you try to express that challenge by climbing them.

It's not a real adventure when you have to pay for it.

I have to admit I do get a bit depressed at times and you know I think about the good old days when I was charging ahead.

June [Hillary] had been doing all these things - the Himalayas and all the rest of it - so we had done things together for a long time, and, particularly as far as our Sherpas were concerned, we had a very sound, I think, philosophy. So that made it very easy for us to agree on what should be done.

While on top of Everest, I looked across the valley towards the great peak Makalu and mentally worked out a route about how it could be climbed. It showed me that even though I was standing on top of the world, it wasn't the end of everything. I was still looking beyond to other interesting challenges.

Many people have been getting too casual about climbing Everest. I forecast a disaster many times.

I did have my moments of despair. It was certainly not - it's not an experience I would like to have again. And then June came along.