"I'd had no idea," he says. "I'd written all these poems about him and I'd wanted one day to meet up with him, and say, 'Look, this is the go-kart and this is the nest, and this is all that stuff.' This was before Friends Reunited. It was like my own Friends Reunited. The hope that one day he'd ring up and say, 'It wasn't like that, I did let you have a go on the go-kart, you know.' And I would have said, 'No you didn't, actually,' and we could get into a wonderful argument about it." But it wasn't to be.
Rosen has had an elaborate domestic life - three marriages, and seven children, including two stepdaughters. The children are regulars in his poetry, none more so than Eddie, his second oldest. It was Eddie who drove the car into a ditch in France, Eddie who screamed in the supermarket when stuck in the trolley, Eddie who played goalkeeper on the sofa with his father. Rosen fans know Eddie well.
When Eddie was 18 he became ill one night, and the next day he was dead. His death, from meningitis, almost destroyed Rosen, who wrote a devastating adult anthology about his loss called Carrying the Elephant, and the equally poignant Sad Book for children. After Eddie died, Rosen went to France with Eddie's mother and he came across a postcard of a man carrying an elephant.
"I thought, oh that's me, I'm carrying an elephant." There was more to it than the weight of despair. "Eddie was very, very big by the time he died - bigger and stronger than me. He used to pick me up ... in fact, on the day he died, I was in a school in Portishead, telling kids about doing his nappy and all the rest of it, then saying, 'D'you know what happened to Eddie? He grew and grew and grew till he got so big, d'you know what he does? He picks me up.' And little children, seeing me and the size I am [6ft 2in], they say: 'No!' He was six-four, six-five. I come in, and he says, 'Hi, Dad,' and he picks me up and puts me across his shoulders and spins me round, and I go: 'Put me down, put me down.'" His tenses sometimes wander when talking about Eddie. "He'd pick me up in a fireman's lift and then spin me round. It used to drive me mad. So, of course, he did it all the time. As an 18-year-old you want to have a laugh at your dad's expense, don't you? So there's part of that picture that's him carrying me or me carrying him at the same time."
Eddie had started working in the theatre, and had already written a play when he died. Sometimes, Rosen will do a show, and a child in the audience will talk about the funny Eddie poems and ask about what happened to him. "And in the middle of all this laughter and chaos, I have to say he died. I always say it - he died. And you see the adults in the room freeze. It's funny; children don't do that. Adults literally become rigid, but children go, 'Oh, right, I like that one where he ...' It's like that's what happens at the end of life - you die. Children know that. They might not feel it in themselves yet, but it isn't loaded with all that ..." He trails off.
After Eddie died, he changed. "I think I probably expressed my upset-ness in a more manic way than depression; getting angry or doing lots of things or trying to find excitement in some place, watching football maybe, trying to find it through activity. Whereas people who describe depression usually describe it in terms of inactivity, which I didn't have and tend not to."
He asked the obvious question: why? He asked it time and again, and received no answer. He decided to write about Eddie's death. "It helped me understand it all. If something awful happens like somebody close to you dying, there is a complete lack of comprehension. You can't figure out why it should have happened and why it should have been you, and then you notice it's not just you." In a way, he says, he nurtured his self-pity, wanting to believe that he was the only person who had suffered such loss. But in writing about it, he began to put it in perspective.
"Just a couple of weeks ago, somebody asked me to do the one about Eddie's birthday and they didn't realise he'd died and I said, 'Yes, sure.'" He began to realise, or accept, that many people have suffered terrible bereavements.
Even now, 10 years on, he keeps discovering new or forgotten things about Eddie. "I find looking at photographs of him difficult, to be honest, particularly photographs I haven't seen for years or photographs I've never seen. Eddie was a good hockey player, and he played in the Arsenal community sports hockey team, and now there is the Eddie Rosen shield presented every year to one of the players. Sometimes they'll turn up and say, 'Hey, we've got this photograph of him,' and that'll catch me."
Rosen says writing about Eddie was counter to his initial instinct and that it was a political decision - not politics politics but cultural politics. "Part of me thinks deep and difficult feelings of any kind we shouldn't really share, but I suppose when I wrote it, it's about sharing the fact that I've had these feelings, and also saying you can have those feelings too, let's share it. If you make things very private and secret, the chances are it will hurt more."
Since Eddie's death, Rosen has married again, and had two children who are six and two years old. "I don't think I'm carrying an elephant any more. I thought I would have to, particularly because in Montparnasse cemetery I met a woman who was standing next to her son's grave and she was crying, and her son had died eight, nine, ten years earlier. And I had the feeling: is that what I'll be like in eight, nine, ten years' time, coming every day to his grave and crying? Part of me thought, oh God, I hope I'm not in that situation."
Becoming a father again has helped ease his grief. Today, he looks positively boyish, his eyes once again full of laughter. Does he think you need to be immature to be a children's author? "No. My guess is to be a successful children's author you have to have either a very close connection with your own childhood or somebody else's or lots of others. The electric connection has to be in place in your brain. How or why I don't know. Take Roald Dahl. He had a very strong memory - both the extremely pleasant and extremely unpleasant memories of his own childhood. He also had an extraordinarily powerful relationship with his own children. Somewhere within all that it enabled him to be a marvellous children's writer."
Perhaps imagination and an undiminishing sense of wonder are the keys. It's amazing, he says, how young children are when they have that sense of play drummed out of them. "On my geography homework I wrote, 'It's windy here on Windermere,' and the teacher put a line through it and said, 'You won't have time for that kind of thing in the exams!'" He belly-laughs.
His laureateship lasts two years; he will be paid £10,000 to deliver eight lectures. During that time he hopes to set up a website on which children can publish their poems alongside known poets. "A place where it can be shared." Literature has such transformative power, he says, and if he can convince just a few children that words can enrich their lives then he reckons he will have succeeded. "I want to help make children's poetry be seen as utterly diverse and a liberating spirit - you can write and read and this helps you discover the possibilities of the world."
I Sell the Owl and the Pussycat a Boat
A previously unpublished poem by Michael Rosen
I loved that little boat
But I needed the cash
So I slapped a new coat of paint on her
And sold her to a couple of newly weds.
I say "newly weds" but to tell the truth
- I know it's none of my business -
They were buying the boat
To go off in to get married.
A sort of honeymoon before the wedding
If you get me.
I'm not an envious person but ...
I'd say more money than they knew what to do with.
I think one of them had made a pile
In the music business.
Guitarist and songwriter.
Lerrrrve songs mostly.
They did tie the knot.
Somewhere on the other side of the earth.
People said the ring was huge.
I don't want to sound mean-minded
Huge - but very, very cheap.
People said it looked like
It had been used for something else altogether.
I heard that it was a Turkish fella
Who married them
On a beach.
To tell the truth -
And I'm not narrow minded -
But we never could figure out
Which was which, if you get me - bride or groom:
The one doing all the lovey dovey singing stuff
Or the one who proposed.
Put it this way:
I never asked
And I was never told.
The only person who might have let on
Was the one who introduced me to them.
A Mr Lear.
But he chose to keep quiet about it.
I'd be amazed if the paint lasted.
It was a job lot left over
From some work I did
At Celtic Football Club.
You can have the rest if you like.
Now what sort of green would you call that?