Facebook has just posted an ad on my page, about a new solar panel scheme in an obscure Midlands town, in a specific road that I lived on, back in 1994. That's at least six years before I actually managed to get on the internet.
The only possible way it could think I have any interest in that road, is that I paused to 'like' an old school-friend's recent post ( he lives in the area, but definitely not on that road ), and that it cross-referenced him with something else on one of mine or my associates pages, and arrived at that location.
Coincidentally, an aunt who rents out the flat on that road, is marooned in a nearby town, after travelling down to our area to do flat-related business. Even so, she's in her eighties, and most definitely not on the internet. And with algorithms, I no longer believe in coincidences, so the calculation that it must have taken to get that result is mind-boggling.
Facebook will be telling me next that the chip shop underneath the flat, still has the Greek family, whose daughter I fell in love with for the entire expanse of time she was in front of my eyes because she looked like PJ Harvey.
It'll be showing me an ad that says: 'Greek PJ Harvey lookalikes still available under this limited-time-only government scheme.'