I joined the navy when I left school because I wanted to see the world. They sent me to the Firth of Forth in Scotland and to Pembrokeshire. I didn't get far.
There are plenty of places I haven't been that I'd like to see. I've been on the edge of the Gobi Desert but I wish to goodness I had been across it or deeply into it. That would have been wonderful.
I'll never forget when I first dived on a coral reef. It's an experience that lots of people have today, so it's easy to forget what a great privilege it is. Not only are you able to move in three dimensions, but the complexity and beauty of a coral reef is just unforgettable. It is one of the most extraordinary revelations in the world.
As a boy I used to spend the holidays fossil hunting on the beach in Anglesey. I've always been fascinated by the very early beginnings of life.
Back in the 50s, I thought I'd had it one night. I found myself sailing a small boat, trying to get to the giant lizards on the island of Komodo in Indonesia. We got into a whirlpool and had to wrestle all the hours of the night until a tide change, when we managed to get ourselves safe.
I've often joked that it must be fun being a sloth, when all you have to do is hang from trees and chew leaves, but I am perfectly happy as a human being.
My idea of a holiday is staying at home. I couldn't bear to sit on the beach for more than five minutes. That sort of holiday is for families, so the children can go away and make sandcastles.
I think for people who want to explore, there is no thrill like it. I'm working on a programme at the moment called Frozen Planet and I got to both the North Pole and the South Pole. That's a pretty extreme adventure.
If you only learn one phrase in another language, I'd recommend 'one more beer'.
Sir David Attenborough presents the First Life series on board now.
