It was when the green Spiderman pants ended up on the grocery shop counter that I realised I had entered a new phase of motherhood. The porridge oats, big pack of raisins and check out woman all looked at me rather unforgivingly as I balanced yet more unlikely items – a rabbit-headed whistle, two toy cars, a miniature helicopter with moving propellor blades, a book about farm animals, three used tissues and a rubber band – alongside. My wallet still eluded me.

Red-faced and too many minutes later, I was out of the shop with an overflowing handbag slung over my shoulder; porridge and raisins in either hand. When did I become a walking children’s junk collection, I wondered crossly pounding across the road. This impossible, unpractical, unliveable fullness of my handbag had encroached on me unwittingly; its smart exterior belying its contents which were dominated by the beloved accoutrements of two year olds and those essential maternal supplies. I started to work backwards.

This cross-contamination of child and adult spheres – my handbag had been exclusively mine up until only a few months ago – must date to the absence of nappies, I worked out. The children drinking out of cups and normal water bottles might also share some of the blame. More significantly, at the same time as gladly abandoning those bulky artefacts of babyhood, we had consigned the big red bag (which with its Mary Poppins’ capacity screamed ‘small child’ even when not dangling off the back of the buggy). Of course, these events, these markers of childhood had brought associated joys and increased levels of independence, but my handbag had certainly suffered.

You see, now there is new stuff. Which self-possessed child would go anywhere without a toy car and rye cracker in hand? Which self-possessed child would accept having snotty tissues pushed back into their own pockets? And which self-possessed mother would go anywhere without a spare pair of green spiderman pants ? Then, invariably, within five minutes any beloved item is cast aside in favour of a more interesting object, usually belonging to another child. Before I have remembered to cast out the unwanted paraphernalia, the car becomes a digger, the pants must be accompanied by socks, and the crackers have crumbled into a thousand crumbs leaving a perceptible trail over my every last belonging.

This morning in a moment of exasperation and knowing I had three childless hours ahead I switched handbags. Paying for an expensive face cream, I found Mister Clever and a strawberry hair slide. Perhaps this is another sort of coming of age.