To a journalist, a one-off event is an exceptional, anomalous moment. However, two such occurrences make an emerging trend.
So I was greatly interested to hear that my mother has also decided to give up supermarkets, and to try to rely solely on her local shops.
She does not live in Brockley, but in Isleworth, a south-west
It was the arrival of a new fish shop in a nearby small-scale high street that triggered her Damascene conversion.
And at the moment she says she's doing well, feeling good about putting her money where her mouth is, as well as saving a little money.
"I went in and bought some mackerel the other day and it lasted for three or so meals," she says. "I hope that by shopping locally I'll not only be able to support local ventures but also save some money."
It's not without its other costs though.
"I know that people complain about going to the supermarket, but I do miss it a bit. The whole ritual of getting into the car, parking up and then choosing everything at once, there was something quite enjoyable about the whole thing."
She is – probably to her credit – less dogmatic than me, in that she will go to supermarkets if necessary. I, on the other hand, have not been to one for some three weeks now, and will not enter one again for as long as this experiment lasts.
It is a curious coincidence that we both chose to give up supermarkets at the same time. Obviously we share a cultural background, and so look at the world in much the same way, and that explains some of the coincidence.
However, I can't help but wonder whether this is part of something bigger, a wider reaction against fast-food culture, anonymous retailing and agro-business.
There is also the looming economic downturn. While the severity of this is unknown, the alarmist headlines in our newspapers will be focusing many peoples' attention on their spending habits, particularly coming just after Christmas. As a result, a new era of earnest engagement with the locality may be emerging.
It's possible. But it may just be me and my mum!