Barbie's birthday - with her biggest fan
In half a century...
Let me introduce you to Barbara Millicent Roberts. In fact I am holding her in my hand. To you and me, she is called Barbie. And she has hit the big five-o, according to BBC.
In half a century, it is thought up to a billion of the dolls have been sold - and there are around 100,000 avid collectors worldwide.
None are more avid than Bettina Dorfmann - and she has a Guinness World Record to prove it.
Walking up to the front door of her unassuming semi-detached house in suburban Dusseldorf in western Germany, there is no immediate indication of what is to be found inside.
Forget stamps, pottery, or anything else you might care to collect. The chances are you have fewer and are less enthused by your hobby than Mrs Dorfmann.
Blonde and petite, she does not look entirely unlike Barbie herself.
Although a likeness to her heroine barely seems necessary in a house like this.
She owns 6,000 Barbie dolls. There is an entire room devoted to displaying 1,500 of them, another 1,000 in other rooms around the house - and 500 in boxes in the cellar.
About 3,000 are on show at exhibitions and museums around the world - from Asia to Europe.
There is one obvious question. Why?
`108 inspirational careers`
Inevitably, it is a question the 49-year-old has faced a little more than once before. However, her enthusiasm remains undimmed.
"I love Barbie. I grew up with her, she appealed to me in my childhood and she still appeals now," Mrs Dorfmann says.
"They are great for children. You can wash their hair, change their clothes, buy new outfits - and in my case display them in glass cases!"
In an upstairs converted office, there is now barely room for the computer in the corner.
A melange of colour strikes me from every direction - blues, greens, reds, yellows and turquoise.
Barbie`s outfits are as varied as her CV.
Manufacturers Mattel say Barbie has had "more than 108 inspirational careers". Many of them are displayed here - Barbie the air hostess, Barbie the ballroom dancer, Barbie the zoologist, and Barbie down the years.
"These are my favourites," Mrs Dorfmann tells me, gesticulating towards a case with at least 50 dolls displayed.
"These are from the Mod era, 1967-1972. They have fantastic clothes, very colourful outfits, different haircuts and different hair colours. They are happy dolls, carefree, that`s why I love them so much."
So just how much can a bit of plastic and a head made from PVC actually cost?
A striking, provocatively dressed Barbie stands alone on a wooden ledge.
To the uninitiated she looks very similar to the thousands of others around her.
"This is the most expensive doll in my collection," Mrs Dorfmann proudly says, as she carefully picks it up, by the feet.
"It`s Barbie Pony Tail Number 1. It is very important that she has her box, her glasses, her swimsuit, her shoes and her earrings. It must be complete to fetch a high price."
"This particular doll is worth 8,000 euros!"
A doll that is worth as much as a small car - just over £7,000 or $10,000 at the current exchange rate - is quite something.
Passion and enthusiasm
As Bettina enthuses, there is a passive indifference from her 17-year old-daughter, Melissa.
Like most young girls, she liked Barbie once. And like most young girls, she grew out of it.
But given the scale of her mum`s collection, she is beyond being embarrassed and discreetly heads to her room with a friend.
On the wall behind us is a framed certificate from Guinness World Records - documentary proof of what is quite obvious. There can`t be many more passionate Barbie fans anywhere.
So when will the collecting stop?
"Never!" Mrs Dorfmann answers, immediately and instinctively.
"I would like at least 10,000 dolls - and I particularly want a Barbie called Franci that was sold in the 60s - and only in Japan."
"It could take some finding, and it could cost me a lot," she adds. "But I will keep looking. Everywhere I go I ask people: `Do you have any Barbies to sell?`"
To help pay for her hobby, she has found a niche in the market.
She has set up a mail order repair service with dolls arriving here from all over the world in the post.
The cellar acts as her workshop, and has a somewhat macabre feel - as I find myself stepping over a carrier bag full of Barbie heads.
A couple of naked, legless Kens - Barbie`s long term boyfriend until their split in 2004 - lie on a table.
Bizarre, yes - and Mrs Dorfmann implicitly acknowledges that her hobby is not exactly mainstream.
But she revels in the passion and enthusiasm for it - and that is hard not to admire.