Friends have suggested that I am the least qualified person to talk about happiness, because I am often down, and sometimes profoundly depressed. But I think that's where my qualification comes from. Because to know happiness, it helps to know unhappiness.

My closest friend, who died not long ago, is buried near Marx's grave in Highgate cemetery, so I see the gaggle of admirers laying roses at the foot of his tombstone regularly. I have never been tempted to leave flowers there myself. Great theories, shame about the practice. Marx did many things. But inventing class was not one of them.

By asking the question 'Am I happy?,' and via the answer setting out what I mean by happiness, there is a political route that can be taken, by asking another question - 'Can politics deliver happiness, and should it try?'

Sometimes Jonathan [Powell] and myself would go to Tony [Blair] and ask him if he was absolutely sure about this or that. That was our job. But ultimately it was his decision.

My aunty says I'm the double of my father. He was a workaholic, which I've definitely inherited. And like me, he could be the life and soul of the party, but also quite withdrawn.

There are many reasons for the decline in royal esteem. One is that so many of the royals are thick.

What concerns me is that the Independent is going, and there are job cuts at the Guardian, but the wretched Daily Mail is still rampant, making lots of money by millions of people clicking on pictures of cellulited women. I think that's sad.