Everything in the changing bag, and what you actually used

Take the changing bag off the hook and put everything in it on the floor.

Most people find somewhere between twelve and twenty things. Most people used three of them today, and the same three yesterday, and — if they are honest — the same three most days since about month four.

This isn't a failure of packing. It's what happens when a bag is assembled out of anxiety rather than experience.

The three tiers

Tier one: the actual bag. Nappies, wipes, one spare outfit. Snack, once they eat snacks. This is the bag. Everything else is optional and you already know it.

Tier two: the just-in-case. The second spare outfit. The muslin nobody has used since the newborn months. Sun cream in November. A hat for the wrong season. These weigh almost nothing individually and collectively double the bag.

Tier three: the archaeology. This is the interesting layer. A dummy that hasn't been used in eight months. Half a rice cake, fossilised. A sock. One glove, never both. A hospital wristband from a very specific week you'd rather not repeat. Sand, if there was ever a beach.

"There is a sock in there that has never, at any point, fit anyone in this house."

Why nobody edits it

Because the bag isn't really packed for the trip. It's packed for the worst version of the trip.

Every unnecessary item in there is a small argument with a scenario: the nappy that leaks through two layers, the sudden cold, the two-hour delay. Carrying it is how you buy the ability to leave the house without running the whole simulation first.

And it does get lighter, eventually. Not because you become braver, but because the scenarios stop being plausible. You can date a family's entire first year by watching that bag shrink.

Worth writing down before it changes

This is one of the few things that is genuinely funny later, and one of the least likely to be recorded.

• What's in there right now — all of it, including the fossilised things
• The three you actually use
• The one thing you'd never leave without that nobody else would think to pack
• What you carried at three months and no longer carry at all

Take one photo of the whole lot on the bed, laid out. It takes ten seconds and it is a surprisingly complete portrait of a stage of life — everything you were worried about that year, in object form.

The last version

At some point the bag becomes a bag. No nappies, no spare outfit, no muslin. Just keys, a phone, and something to eat.

That transition doesn't have a date either. But if you photographed it once, laid out on the bed, you'll be able to see exactly what you stopped needing — which is another way of saying exactly how far everyone came.