I lived across from a farm field, and noticed how dusty in the inside of my garage (and it's contents) got if I left the door open. I didn't put two and two to

I lived across from a farm field, and noticed how dusty in the inside of my garage (and it's contents) got if I left the door open. I didn't put two and two together and realize it was from the field until one spring when I noticed a fine layer of what smelled like manure on my bicycle.