What's a scent from your childhood?

Fresh cut hay mixed with dust and diesel fumes. We baled square bales, almost no one does that here now. When you started up the baler always needed a bit of fine tuning to make sure the knotters were tying properly and the tension on the strings was right and I spent a lot of time walking behind the baler and watching it work. There's an unmistakable sound to those old square balers as the plunger comes back packing the hay into the chamber and the tractor engine loads up a dozen or so times before it trips, ties off, and starts the next bale.
It's been a very long time now, the field where I spent so much time walking behind that baler and where I later learned to drive was planted in pines so long ago that those trees have now been cut. My sense of smell now comes and goes so I'm lucky if I smell hay anywhere. I guess I'm getting old.