I think Picasso was, without doubt, the greatest portraitist of the 20th century, if not any other century.

Yes, I did, I mean I painted er, in a kind of abstract expressionist way, because of course that was exciting.

In one gallery they actually had a notice which said No Sketching. How obnoxious! I said, How do you think these things got on the walls if there was no sketching?

On the iPhone I tended to draw with my thumb. Whereas the moment I got to the iPad, I found myself using every finger.

In the end nobody knows how it's done — how art is made. It can't be explained. Optical devices are just tools. Understanding a tool doesn't explain the magic of creation. Nothing can.

The thing with high-tech is that you always end up using scissors.

As you get older, it gets a bit harder to keep the spontaneity in you, but I work at it.