I went to an auction in the late '70s and bought a small Renoir. People said, "Why did you buy a Renoir that size?" I said, "I can put it in the safe with my diamonds." And that was a true story. I bought it to put it in the safe.

The Graff Hallucination is a sculptural masterpiece; a celebration of the miracle of coloured diamonds. For many years I have thought about creating a truly remarkable watch that illustrates our all-consuming passion for diamonds. The Hallucination has made my diamond dream a reality.

One of the great things about collecting contemporary art is that you mix with contemporary people.

You learn about yourself when you're collecting art. You learn what you're capable of. After all, we're not speaking about pennies-we're speaking about vast sums of money. I do it on my own back without advice, so I've got the confidence to do it.

Collecting contemporary art I started with some of the younger artists. Although, having a son who's an artist, I was hesitant-I think he was a little anxious when I bought another young man's work. But it might have encouraged him in the long run.

I went to an auction in the late '70s and bought a small Renoir. People said, "Why did you buy a Renoir that size?" I said, "I can put it in the safe with my diamonds." And that was a true story. I bought it to put it in the safe.

When there's an opportunity, some people pass it by. I've been lucky enough to recognise opportunities and every day, in my business, there's an opportunity somewhere - to buy, expand, design.