Once, I was talking to a new coworker, who lived in the same city as my parents and was flying in weekly to work on a special project. Since I had also lived many years there and we were talking about the city (a major metropolis). It turned out that I had lived in the same area he lived. On the same street, as a matter of fact. Then, he mentioned some routine work that had to be done but fortunately the previous owner had left good documentation on what had previously been done. At that point, I asked him if the pool was still leaking. He was rather surprised, as that was an ongoing problem in the house (going back several owners), and how did I know?
You see, my father is a very meticulous man and a good handyman. One of his quirks is that he writes "house manuals", with detailed instructions on everything in the house: how the electrical circuits are arranged, how the water pump works, schematics of all the circuits and pipes, etc. Since he has lived in older houses with some very weird "solutions" (aka, the previous owners had slapped together some strange way of hooking the pump or the swimming pool, for example), this came in quite handy. When he moved, he would always hand over the manual to the new occupants.
So, when he mentioned the same neighbourhood, the same street and the documentation, I put two and two together: he had bought my childhood home.