More than half of our children have a toy so beloved that, if lost, the whole family feels the pain. What's that all about?

Once Clownie went missing in Amsterdam and had to fly home alone. Amazingly he was there in Norwich when we got back.

(He wasn't, of course, the clown at home was one of our cunningly bought duplicates, but the story we told our then two-year-old was so convincing that I can see the little lost clown, sitting in his own aeroplane seat with his huge embroidered smile and hugged-ragged blue and white striped body.)

When our newborn daughter fell in love with the soft toy I began buying up doubles, for the days when Clownie needed a wash or fell from the pram … or went walkabout on holiday.

Several years later I was astonished when my daughter didn't want to take Clownie, or son-of-son-of-Clownie, on a primary school residential trip. He had been on every excursion to the park, every holiday and sleep-over, and to toddlers, playgroup, nursery and school. Surely he wouldn't want to miss out on all the excitement of an activity-packed school trip? And so began her gradual detachment from the beloved toy. Today there is still a well-worn, oft-washed, faded Clownie in a box of similar treasures in the attic.

He keeps my plastic doll from the late 60s company. Fiona has a hole in her heel and disturbing eyes and my grown-up sons claim to be terrified of her. My husband has a teddy bear who was once called Tedward but is now 'Daddy Bear' in our granddaughter's re-enactments of Goldilocks and the Three Bears.

Our younger son was less loyal to a toy, although there was a difficult episode when Paddington Bear didn't make it to nursery and we had to do a quick drawing of him as a substitute. He was a blanket baby, with a whole succession of soft covers keeping him company through babyhood and childhood. They too are in the attic – not because he can't bear to part with them, but because now I love them, for the joyful, gentle, chatty, blue-eyed, white-blond toddler they summon.

George Dunscombe, of Costessey, near Norwich, is nine and three of the loves of his life are Beru, Hamuel von Hamuelson the first (or Ham to close friends), and Jambon. Beru is a bear he was given at birth and is now so precious he does not leave the house. Hamuel von Hamuelson is a pig, acquired when George was five, and Jambon is his slightly newer doppelganger. Hamuel is a hugely well-travelled pig, having accompanied George on a family trip to Australia, as well as summer holidays in Europe – and sleepovers with friends and relatives. 'He's not embarrassed at all!' said his mum, Rachel (who was once inseparable from a piece of fluffy material with paper eyes, called Fluff, and won in the lucky dip at Aldborough Fair). 'He still won't sleep without Beru or Hamuel von Hamuelson.'

There used to be a second Beru too, but he was lost, making the remaining bear extra precious. 'Once, when he was about two, he found the second Beru and walked up to me with one in each hand, absolutely amazed and overjoyed,' said Rachel. 'Another time he was dropped as we got off a plane and walked across the tarmac – but staff must have seen him and he reappeared, lying on his back and going round and round on a luggage carousel!'

So what is it with these deep attachments to early-childhood toys?

Psychologists call them 'attachment objects' and around 60% of western children have them. In cultures where young children sleep with their parents they are less common. Another word for these favourite bears and blankets (and pigs and clowns) is 'transition objects.' They bridge the gap as children realise they are separate from the rest of the world around them, and particularly from a main carer. Some of the love children feel for their parents, and the adults' power to keep them safe, is transferred to the teddy bear – which children will treat as alive, even though they know it is not.

So, next time you see a teddy bear, gaze into its glassy eyes and know that it has incredible powers, to calm frazzled children, chase away bad dreams, provide company and love – and even find its own way home.

Some famous teddy bears and blankets:

In Charles Schulz's Peanuts comic strip, Linus has a 'security and happiness blanket.'

Winnie the Pooh was the teddy bear owned by AA Milne's son Christopher.

Aloysius accompanied Lord Sebastian Flyte to Oxford in Evelyn Waugh's novel Brideshead Revisited – and is said to have been modelled on John Betjeman's beloved bear Archibald Ormsby-Gore.