It wasn't that long ago that the adventures of Paddington Bear, the polite marmalade-loving ursine charmer from Peru, were an important rung on a child's journey up the literacy ladder. He came somewhere between The Very Hungry Caterpillar and maybe Enid Blyton or Richmal Crompton - next stop improving works for teenagers and, before you knew it, The Catcher in the Rye. Then along came the boy wizard who must not be named, and he gobbled them all up. The End.

But not before Paddington had made an indelible impression on a couple of generations of children. From him they learnt the importance of trying really hard to do well, even if it doesn't always pan out, as well as good manners. Paddington always addresses people as Mr X, Mrs Y or Miss Z, for example. Hang on - he's not a bear at all, is he? He's Robert Robinson.

Another fan must be the someone influential at the BBC who, when the former Children's Laureate Michael Morpugo came along and said: “In 2008 it'll be 50 years since the publication of the first of Michael Bond's Paddington Bear books, would it be OK if I did something about it?”, replied: “Go for it, big boy - and why don't we go the extra yard and oh, I don't know, just thinking off the top of my head here, perhaps we could place 50 Paddington bears in train stations around the UK and, in exchange for taking the bear home, the 50 people who pick them up can ring Radio 4 and leave a special birthday message for Paddington?” And so they did. The End.

But not quite. Because in Please Look After This Bear (today, Radio 4, 10.30am), some of the 50 tell Morpurgo about how and where they found the bears, and what Paddington means to them. So that's very sweet. And Michael Bond explains how he came to write A Bear Called Paddington, the first of 11 books - the next is due out in June - and why he thinks that his creation lives on (there's a Paddington statue at the eponymous station, to remind generations yet unborn). And among the excellent bits of trivia there's the story of how a woman made the first Paddington Bear toy for her son and went on to run the only factory in the world licensed to produce them. And her son went on to become Jeremy Clarkson. And that's the living end.

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