My youngest, Stan, 3, wants to be “a dad” when he grows up. This is something I can advise on. Not only am I his dad, but fatherhood runs in our family. My father was a dad. His father was a dad. And although the genealogical record becomes cloudy in the early 1800s, being a dad is something generations of us have gone in for (mainly on the male side). We know the rewards and the pitfalls. On the plus side, minimal qualifications are required and the - ahem - entry procedure can be unusually satisfying.

On the down side, the hours are long and the pay is poor. So Stan changes his mind. Instead, he wants to be “a pedestrian”.

Again, we point out that this won’t make him rich. It turns out that Stan doesn’t mean “pedestrian”, but “comedian”. (And a round of applause to the nursery staff who are feeding him all these four-syllable Latinate nouns.) We like this idea, which implies Oxbridge, Edinburgh, fame and fortune fronting beer commercials, then a dotage playing panel games on Radio 4.

It’s a shame that Stan’s idea of making people laugh is throwing food over them. Clowning doesn’t have the same middle-class cachet.

Meanwhile, seven-year-old Alfie talks of playing football in the Premiership. But if he doesn’t make it on to the pitch at Stamford Bridge, he will be a doctor. It looks like fun: lots of travel, meeting people, solving their problems. And fighting Daleks.

Poppy, 6, wants to be a primary teacher, though. How should I respond to that? As a parent-helper in school, I can only admire the dedication and vocation of the teachers here. But I think Poppy is choosing teaching only because she wants to keep her options open.

Let me explain: it’s the end of playtime. Down the corridor comes a weeping little boy and a pair of playground “buddies”, coaxing him along with all the seriousness of stretcher-bearers from the Somme. He looks awful. There are red marks across the back of his shirt like he’s been mauled by big cats.

Before I can react, the deputy head strides out of the staffroom and pulls on plastic gloves ready to administer first aid to a bump on our casualty’s head that I hadn’t even noticed. A quick check on the back of the boy’s shirt reveals that the stain is not blood, but berry juice from bushes in the grounds. After extracting a confession of tomfoolery, she scribbles a note to his parents to explain not only what happened, and how to monitor his injury, but the best way to get red juice marks out of poly-cotton.

Florence Nightingale, Quincy, Judge Judy and Kim and Aggie in one five-minute drama. Choosing to be a primary school teacher is like never having to choose at all.

Michael Cook is a freelance copywriter and a parent helper at Ernehale infants school, Arnold, Nottingham, which his children, Alfie and Poppy, attend