Maybe that is simply how most people's memories work. We remember little snippets, like the fact that a train came through while we were sitting in the town square, or the fact that a certain flower was in bloom at that moment, and it's scent filled the air.
We used to have bonfires when I was a kid, but I don't remember the bonfires just how the smoke would lay in layers in the lower spots in the surrounding countryside in the evenings, like little pools of fog.
Yes, sometimes photographs work like triggers that bring things we have stored in the back of our mind to the forefront again.