"Old age isn't for sissies." It was Bette Davis who coined that pithy aphorism, and I'd like to adapt it here: "Potty training isn't for wimps." It sure ain't. In fact getting your toddler out of nappies and onto the loo is probably the toughest parenting challenge there is. It's a path strewn with disaster, setback and failure.

Perseverance and patience must be your constant watchwords as you struggle to make your baby understand that the toilet is the place to do their business, not their pants. Or bed. Or car seat. And I use the words 'parenting challenge' advisedly - because it IS a parent's responsibility, however demanding, frustrating and exasperating it may be.

So the news this week that one in three children entering nursery, pre-school or primary school are not potty trained came as a shock. Because one in three translates to fully 200,000 little ones being dropped off for the day either in nappies or requiring them.

And that's new - 15 years ago no one would have believed it. Yes, a little child might soil themselves in class out of fear, or illness, or just a plain old piece of forgetfulness - but 200,000? What's happened to us? And will this get worse before, or even if, it gets better?

It's not that modern-day toddlers are somehow more resistant to potty training than previous generations. It's simply that a substantial minority of parents today don't believe that getting their children out of nappies and into dry pants is THEIR job. They think it's perfectly acceptable to leave the whole thing to teachers, nursery assistants or carers. It reminds me of a classic episode of The Simpsons, where Homer runs for election on the ticket: "Why can't somebody else do it?" He wins by a landslide.

But we don't live in the Simpsons' absurdist, cartoon community of Springfield. Out here in the real world, it's just not OK to expect nursery or school staff - who already have enough on their plates - to take on the complex task of toilet training too. I'm not finger-wagging here, but my message to such parents is: DIY. Do it yourself.