There's no formula. It just happens or it doesn't. And, fortunately enough for us, it happened.

Weight doesn't matter as long as you're happy with yourself.

In the next few years I'd love to play a female version of Doctor Who. I know exactly how I would play her - she would be crafty in a clever kind of way.

Rose has had adventures and she's a lot more confident as a companion. She's on a par with the Doctor, more so than last year. She's seen some incredible things, terrifying things. This time she's more experienced as a woman, as a companion; she does everything with more conviction. There's stuff that she understands a bit more, so it's a natural progression.

You want it to happen, but at the same time you don't want it to happen. It's one of those weird things like Ross and Rachel, you want them to get it back on but you don't.

There are lots of places for Rose to go. I have had a ball. I might still be here in 40 years.