My mother was trying to get her three-year-old grandson Calvin into his car seat. He wasn't co-operating and, in time-honoured fashion, she told him sternly, "I'll count to three."
For me and my sister, growing up, that was enough: as she once said, if we were foolish enough to let the count finish we deserved whatever we got.
My nephew is made of cockier stuff. He shot back, "Why not count to a hundred?"
His sister Juliette, almost seven, has her moments too - once, I asked her, "Have you been good?" and after a pause she replied, "I'm afraid I can't answer that question" (a career in politics may beckon) - but the differences between brother and sister are already marked, and conform somewhat to boy-girl stereotypes.
He's brash and permanently active, the sort of kid you can't take your eyes off for a moment in case he disappears or does something he shouldn't. And he has recently gone through a phase of biting (his mother did too, though I believe I was her only victim).
She's always been a bit quieter and less constantly in motion, and she loves animals - she's already voiced ambitions of wanting to be a vet. Not that this is immutable: at her age, I seem to recall, I wanted to be a fireman.
Seeing the children, as I do periodically, it's hard not to make comparisons and observations. He's starting to look a bit like his mother and grandfather, but it's hard to detect a family resemblance in her, though I'm sure it will come. And every time I see them, I notice changes.
They've both pretty much ditched Diego and Dora the Explorer (none too soon) are developing individual tastes - for instance, he loves Peppa Pig while she's an Octonauts fan - and while the occasional tantrums and bouts of stubbornness can be wearing, they're inevitable and simply have to be borne (admittedly in my case, mostly from a safe distance). .
My sister said she used to see parents with screaming children and feel for the kids; now her sympathies tend to lie more in the other direction, and I can see what she means. However, I still remember one kid I saw in the street proudly proclaiming to his mother, "I'm a mongrel dog of a child!" and thinking there was probably a less than pleasant story behind that.
Juliette and Calvin are the closest thing I have to children and, while distance may lend enchantment, it is always a (slightly exhausting) delight to see them.