Just curious.... I'm not talking Proust's madeleines or the food that reminds you of childhood, so much as particular food things that remind you of something quite specific.
I work from home and when my dp is due to be out in the evenings I quite often grill peppers at lunchtime in advance for dinnner (he doesn't like them). And every time I do it - like today - and the house fills with the smell, it reminds me of the day eight months ago when my waters broke. The peppers were still in the oven when dp put it on to warm towels for the baby eight hours later...