I couldn’t believe my youngest daughter’s reply when I told her to stop leaving the tap running at full power while she cleaned her teeth.

“There are people in some parts the world with no water at all,” I said, to which she replied: “Well they wouldn’t be able to use this water.”

Children are so wasteful. Well, mine are. They go from room to room turning on every light in the house, never considering switching them off again.

They shower like there’s no tomorrow, use the washing machine to wash one item and leave their radiators blasting out heat when they’re out.

They plug in dozens of gadgets, leaving so many trails of sockets and wires that their rooms look like a branch of Curry’s.

It seems crazy when you think that children are brought up in a society which places recycling at the top of its agenda.

“Can I have a new school jumper - this one has a hole in it,” my daughter asked.

I had a look and the ‘hole’ was the size of a lentil, yet she wouldn’t consider stitching it up. When I told her we used to darn socks she laughed.

Nowadays, holey socks go in the bin.

Obsessed with the three Rs (Reduce, Reuse and Recycle, not the other one) I’m always finshing them out to use as dusters or on the rare occasions I clean my car.

“But you never clean your car, what’s the point in keeping them?” my husband will say, as the pile grows of old socks, old shirts and old bedsheets - all which I believe will ‘come in’ at some point, rises by the week.

What I can’t understand is that on one level children are obsessed with saving the planet - my eldest daughter collects paper for recycling and insists we wash out and take Tetra Paks to the tip - but on the other she leaves every electrical item switched on.

My daughters turn their noses up at food that’s as little as a day past its sell-by date, whereas I’ll eat some things, yoghurt, for instance, a couple of weeks beyond rather than throw it away.

Teaching them to use resources wisely isn’t easy.

I always turn off the central heating at night, but I went to bed before everyone else last weekend and it was left on.

It was like sauna when we got up next day. “It’s lovely and warm - is this what other people’s house are like on a morning?” my daughters asked.

I was so cross I forbade them from turning it on for 24 hours.

Harsh maybe, cruel - definitely, but it’s the only way they’ll learn.