I visited the offices of Pan Macmillan last week to interview William Horwood, he of Duncton Wood fame, and in the process got chatting to his editor Julie Crisp about the children's books which hold up on rereading as an adult. It was sparked by Horwood's moles, which, we both agreed stand the test of time (although both of us had failed to
notice the incest when we were children, adding fuel to my censorship-is-pointless theory that kids take what they want/need from books, ignoring the rest).

But, as someone who is slightly obsessive about buying old children's books from secondhand shops and reading them when I need to relax, there are so many which fail to live up to an adult perusal. I have recently been bitterly disappointed by Robin Jarvis's The Deptford Mice after buying the trilogy in Hay-on-Wye this summer – I had memories of a horribly scary orange cat, dripping sewers, courageous mice. Yes, they're all still there, but as a child I hadn't noticed the horribly clunky dialogue (I quote at random from the book in front of me: "We ain't gonna give you our luvverly grub you old fool – not unless you got summat to swap"). It made it impossible for me to read on.

Aged 11, I'd absolutely adored Black Trillium; I forced my boyfriend to read it in my early 20s and after getting a couple of chapters into it he looked at me as if I was mad. Trying it again myself, I could see why – the story I'd loved so much ("One stormy night, three princesses are born...") was simplistic and frankly a bit rubbish; the writing, again, almost unreadable.

You won't be surprised by this one, but still, it made me sad: I bought a gorgeous 60s copy of Enid Blyton's The Mountain of Adventure last month (I'd remembered it as my favourite from the Adventure series – the ones with Kiki the parrot – as I had vague recollections of Philip somehow being able to fly). Not only did it have appalling racial stereotypes – the Welsh ("Effans, Effans, they have come, look you!"), a black man ("I done told you go 'way. Bad mountain, dis") - but the story is just plain stupid. A mad old genius who is using "some rare metal or other – like uranium" to make wings? Hmm.

And over the last few weeks, a friend and I have been attempting to relive our childhoods by rereading Francine Pascal's Sweet Valley High books (writing all this down, I realise I am sounding quite odd – I do read grown-up books as well). They are ridiculous. Cliche-ridden, silly, pounding home their moral message (Don't Go Home With John is even one of the titles, for heaven's sake) – why I ever dreamed of going to an American high school I just don't know. Oh – and when I was little, Elizabeth, the studious, sensible, clever one, was always my favourite. Now it is by far and away the irresponsible, just-wanna-have-fun, Jessica... How times change.

Of course, there are absolutely loads of kids' books which are just as wonderful on an adult read. Susan Cooper. Tamora Pierce. Alan Garner. Lloyd Alexander. Douglas Hill. Anne Fine – all authors I regularly go back to for a pick-me-up when I'm feeling low. I was reminded of another last week by Julie at Macmillan: Pat O'Shea's The Hounds of the Morrigan – I reread it a couple of years ago and it was still an absolute beauty, as was Mary Stewart's A Walk in Wolf Wood, William Sleator's Interstellar Pig, Gillian Cross's The Demon Headmaster and oh so many more. But I'm in the mood for criticism this morning, so please tell me about the children's books which, picking up again as an adult, you've been shocked to find aren't, actually, any good.