When is a joke not a joke?

A 10 year old boy walks into a kitchen and tells a joke:

A man walks into a bar, and says "Ouch".

A mother pauses, thinks, and laughs. “That’s funny” she says. “That was a first” she thinks. He has told her a joke that she didn’t already know, that she found genuinely funny, and that wasn’t followed by “d’you geddit?” and an explanation.

Ten years ago, she wrote his milestones in a book. They came thick and fast. The first tooth, the first steps, the first words. They come less often now, but they still come. The first filling, the first soccer goal, the first real joke. She doesn’t write them down any more. Then there are the kind that she couldn’t write down anyway. They’re not “firsts”, they don’t stand out, they creep by slowly, and when she notices them, she is already looking back. He doesn’t need a spoon to eat peas. He doesn’t always choose from the kids’ menu in a restaurant. He sometimes empties the dishwasher in the morning, not because he’ll get a sticker on a chart, not because he's proving he can do it all on his own, but just to be kind. When she sorts the laundry, his socks are easy to muddle with hers. The golden window between his bedtime and hers is getting smaller; it’s more of a chink than a window already. The park is no longer about the swings and slides. She can’t dribble a soccer ball past him, but he can get one past her, every time, easily.

She needs his advice on school matters. She remembers it was she who decided it was time to replace the Bob the Builder lunch box, but now it is he who tells her that Spongebob valentines won’t do for fifth graders (though he can't tell her what will).

Soon will come the milestones hidden from her view. The first joke he hears that he doesn’t think he should tell her. She knows these days are not far off. Perhaps they are already here.

A mother walks into a milestone, and would say “Ouch”, but mothers don’t say that, and anyway, this one is a fun kind of a milestone. A mother walks into a milestone, and keeps on walking.