You see these shuffling rows of shiny faces, waiting for their turn, so they're very dedicated to the program and desperate to know what it is they've got - so often, they have no idea.

When I was introduced to the crew on the first occasion, I told them I didn't expect to enhance it - I'd just try not to damage it!

What I will learn over the years will be of benefit and interest to me personally but, as far as the program is concerned, I'm the mouthpiece of the viewers as well.

People's reactions can be surprising but, if you have overwhelming news, I suppose the only thing you can do is just look, because you're stunned.

One of the experts bought his first piece at the age of four, so they did start very young, most of them. They did it out of genuine interest but today's kids are much more materialistic and there's a danger, I suppose, that they might just be out to make dosh.

It's nice to witness these discoveries at first hand.