Playing in my early bands, working as a studio musician, producing and going to art school was, in retrospect, my apprenticeship. I was learning and creating a solid foundation of ideas, but I wasn't really playing music.

I wanted to emulate music from America - young punks playing rock n' roll is what it was. I read part of Keith Richards' autobiography, and it was totally parallel with me, learning from American records.

There's such a currency to Led Zeppelin, or the members of Led Zeppelin. If I put it to you this way, on the run-up to the O2 concert, the only music that we played was music of Led Zeppelin - the past catalog stuff; that's what we played on the way towards shaping up the set list for that. But we played really, really well.

You get a chance like that maybe once in your lifetime, and you are lucky to sustain it over that period of time. It doesn't mean to say that whatever I do in the future has no substance to it - I may present some new material I've got, and there are definitely new angles of doing it - but I'm not looking to recreate another Led Zeppelin.

I'm trying to stay as calm as possible and focus one day at a time, but when reality sets in, I feel everything: anxiety, excitement, nerves, pressure and joy.

Happiness needs one-upmanship.

I am glad that I wrote something that brought joy to millions of people.

Cleanses and products don't make you look more beautiful. They certainly help, but if you reach contentment, you're set. My makeup artist, Melanie Iglesias, couldn't figure out why my skin looks so good. I think it's because I'm happy!