Well, it's always very difficult to say what prompts anybody to do anything, let alone getting underwater and teaching ravens to fly. But I think it probably all dates back to a very early age, when I was quite a young fellow. My mother, Lady Beryl Streeb-Greebling, you know, the wonderful dancer - 107 tomorrow and still dancing - she came up to me in the conservatory - I was pruning some walnuts - and she said "Arthur" - I wasn't Sir Arthur in those days - she said "Arthur, if you don't get underwater and start teaching ravens to fly, I'll smash your stupid face off," and I think it was this that sort of first started my interest in the whole business of getting them underwater.