There's nothing quite like the terror of backtracking through the shopping mall calling your child's name and spinning round frantically, trying to see in all directions at once. The longest this has ever happened to me was about three quarters of a minute one busy Saturday before Christmas.
It's nightmarish. The imagination goes wild with all kinds of unthinkable things. Mike was two aisles away, picking the currants out of the fruitcakes.
When I found him, I grabbed him and roared all kinds of dire threats if he ever dared stray from my side again. I scared the bejesus out of the poor kid for doing nothing other than being a kid.
The problem is that we all have the image of Madeleine McCann burned on our brains. I know, rationally, that the chances of anything similar happening to one of my children is utterly remote, but when the chance exists at all, it's impossible to be sensible and proportionate.
It's like Russian Roulette. You've only a one in six chance of losing, but the consequences are so dire that you'd be better to stick to table tennis.
One of the many downsides of this irrational anxiety is that we're communicating it to our kids. If either of her two younger brothers disappear round the next corner, my six-year-old Annie goes into meltdown.
"Daddy, Mike is missing! He's lost!" I have to remind her that she's not the mammy and that the kid is fine. She's actually driven herself to tears from anxiety, and she's never even heard of Madeleine McCann.
All kids these days spend their waking hours under constant supervision. You see a kid walking alone along the footpath and you look behind him expecting to see at least four shady looking characters in long coats and mirrored sunglasses following.
There was a story in the papers recently about an American woman, Lenore Skenazy, who runs a website called freerangekids.com. She says on her website: "We just do not believe that every time school age kids go outside, they need a security detail." So she set up a new holiday: "Take Our Children to the Park . . . And Leave Them There Day."
The idea is to let children off the leash, to have the "unsupervised, unstructured" play that is more or less unheard of these days. Unsurprisingly, most of the media in the US went mad at the idea. One guy called it a "paedophile buffet". But it went off without a hitch.
Skenazy is encouraging a lifestyle kids had when I was a boy, where everyone just ran around eating worms and screaming at each other and nobody paid a bit of notice.
My eldest is six, and that is my excuse for deciding that no, this is not for me. But even when she's 10, or 11, or even 12, am I really going to leave her off to the park on her own? Will I let her cycle to a friend's house? To the shop? It's kind of like electric cars and lentils. Yes, these are good and positive things, but not for me.
There's another side to this, too. I was in the park with my three children a few weeks ago. I was pushing Annie on the swing and this little blonde girl came up, sat in the empty swing beside Annie and tried to push herself off, but couldn't, so she looked back expectantly at me. At that moment, I'd rather have been confronted by a mugger.
There are few things more terrifying to a mature man than small, unattended children. I took a step back and looked around frantically for whoever might be in charge of this little girl, but no one appeared.
Eventually, I decided I was being ridiculous and managed to get her swinging by awkwardly holding the chains -- just so I wouldn't have to touch her. This is daft, but I've heard worse -- a guy in a swimming pool who thought twice about going to help out a little girl in difficulty.
As with leaving your kids unsupervised, the chances of a kid taking a notion and deciding you did something you didn't do are utterly remote, but who wants to take that chance? Not me. Little girls, stay the hell away.