The last black Waterman ink cartridge had run dry, there was not enough even for a signature, and it’s only a fish-like scrawl. A black Bic pen is fine for a shopping list, or writing a number on the back of the hand (still not having mastered the knack of entering it directly into the iPhone, that most simple of smartphones), but Bic pens do not feel write for writing important stuff; there is a sense of gravitas in writing in black indelible ink, probably derived from a subconscious association with its use for entering details into registers of baptisms, marriages and burials. (The church archivist in the 1980s warned against the use of biros for such purposes, complaining that entries in biro in the 1960s had by then so much faded as to be illegible). Whatever the reason, words written in black ink with a cartridge pen seem to have a weight and solemnity that is lacking with a biro or a roller ball.

So it was that a trip was made to WH Smith, to buy a packet of eight cartridges costing £4.99. Of course, it meant an encounter with the stationery shelves, an experience that generally means going home with things that one does not really need. (It’s like going to Lidl, one goes into the store for bread and milk and comes out with various foodstuffs and a tenor saxophone: a colleague once had such an experience).

What is it about the stationery shelves in Smith’s that makes one spend money unintentionally? Is there an association with childhood years and buying new things for going back to school? Is it an association with student days and buying pens and paper and binders for going back to college? Does it evoke thoughts of starting a job and the feeling that one should be equipped with a good diary and a good writing pad and a good pen in order to look competent and efficient? Or is it something else? Is there something exotic about the miscellaneous items that one is tempted to buy, even if they are never used? For a compulsive shopper, WH Smith is a place to be approached with wariness, otherwise one goes home with a stapler that is not needed, or index cards that will never be used, or a set of highlighter pens that will never highlight anything.

Resisting the urge to buy a 2017-18 academic year diary, I went to the checkout.

“£6.48, please.”

The Waterman cartridges at £4.99  – and a packet of pencil erasers at £1.49: one cannot just buy one thing.