If your childhood had smell, what would it be?

Cow manure and soft pretzels. I lived in farm country and we had a soft pretzel factory about 1/4 mile away and we could smell both every day. We used to get the reject pretzels from the factory. They would set them outside in a big bucket for anyone who wanted them.

Mine would be pine needles and lake/ wet dirt.

The smell from box (buxus) hedges after the dew had settled (and been sprayed off by a child's (my) hand.

I used, as a 4 or 5 year old, to run between two box hedges with my hands spraying water off both sides.

I have only to smell a wet box hedge to lose over 50 years.

Coal dust. As a kid I shoveled coal into tenement furnaces to make some money.

The aroma of my grandma's flower, veggie, and fruit garden.  I can smell the plum blossoms now!