The perfect, unpretentious, well-constructed party bag was given to guests leaving a recent Hatchards party. It contained a wedge of farmhouse cheddar and box of cheese biscuits from Paxton & Whitfield, a bottle of good white wine and an elegant hardback copy of Lucky Jim.

The next evening, I tucked into all of these simultaneously, feeling spoilt, and meditating on how much nicer they were than some of the tat my children used to bring home from birthday parties in white polythene bags: a slice of synthetic birthday cake oozing its jam on to tadpole-sized balloons (which wouldn’t inflate, however hard...