I think Himalayan climbers tend to mature fairly late. I think most of the successful Himalayan climbers have ranged from 28 to just over 40, really.

I get older I get more cantankerous, but June [Hillary] gets a bit more cantankerous, too.

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.

Mount Everest, you beat me the first time, but I'll beat you the next time because you've grown all you are going to grow... but I'm still growing!

There are lots and lots of challenges that I wished - at the time - that I had done.There are lots of occasions where there were exciting things to be done but for some reason or another it was physically impossible for us to do them. I still wouldn't mind if I was able to go down into this most impressive valley in the Antarctic, but of course those things are beyond me now.

When I was 50 years old, I actually decided to draw up a list of half a dozen things that I really hadn't done very well, and I was going to make efforts to improve. One of them was skiing, and I really did become a very much better skier.

I've always hated the danger part of climbing, and it's great to come down again because it's safe.