Conversation overheard the other day in the Ladies at Sainsbury's: Small boy (washing his hands): "Green soap!" Mother: "Yes, the soap's green."

Small boy: "Why?"

Oh, don't we know that eternal 'why', we parents and grandparents of three-and-a-bit-year-olds. No matter what you say, on any subject, it pops up in answer, almost if the toddler was programmed.

Sometimes it's used as a kind of protest, shorthand for: "Why should I do this when I don't want to?" To which the answer is usually something along the lines of: "Because it's good for you"; "Because we need to wash off the germs before we eat"; or even: "Because I say so".

But most of the time the 'why?' is much more complicated than that. He wants to understand, he wants to know. He has a genuine curiosity about the world around him.

So, you try and explain, sometimes at great length. And then, like as not, just when you think you've finished, that 'why?' pops up again, and you have to go back to the beginning and try and word it all a bit differently.

Or you can do what that young mum in Sainsbury's did, and make a deft change of subject, holding your breath that the child won't say 'why?'

to that too. After all, how are you supposed to know why the soap's green?

Some things just are, without any good explanation.

There's one thing I'd like to know the answer to, though. Why do nearly all public loos have hot-air driers in them? All right, I do know the answer to that one: because they're a lot cheaper than towels, whether paper or otherwise. They're probably also supposed to be more hygienic.

I'm not sure about the hygiene bit.

I'm a bit suspicious of all that hot air blowing at you. And maybe they are cheaper for the owners of the premises than all those diposable towels, but I'm not convinced they're any better for the environment. They must use a lot of electricity.

But whatever the arguments in their favour, as a user I loathe them.

Either they deliver a blast of heat so fierce your hands feel sore, or they let out such a feeble trickle of air that you give up and finish the job with a surreptitious rub on your skirt.

The one thing I know for sure is that most small children hate them. Well, just imagine what it's like being a toddler, faced with one of them. There's this machine a good way above your head that suddenly lets out a great roar and blasts hot air right at you. No wonder so many little ones end up screaming in terror.

I've been in supposedly child-friendly loos (London Zoo's is a case in point) where there are baby-changing mats and child-height wash basins, but it's all ruined by the hot-air driers. Clearly, no one who's ever cared for small children was asked to advise when these places were set up. Wise mums and grans take along their own wipes or tissues rather than subject their children to the dreaded drier.

So, full marks to Sainsbury's, with its green soap - and its paper towel dispenser alongside the hot-air driers.

Alright, hot-air driers are a trivial matter in the general scheme of things. But there are lots of very much bigger questions that need to be asked as you go through life. That toddler with his eternal 'why?' is getting in some useful practice.

Published: 26/05/2005