After WWII, My Grandfather and Dad went down to the Railroad yard that was near our Town and tore apart Jeep crates, pulled all the nails from the boards. All nails were saved, and straightened. While my Dad was in Europe (Battle of the Bulge) my mom bought a small lot in town and after the war they built my Parents first house. Years later my Dad secured a building that needed to be destroyed. So my brothers and Dad tore down that building and hauled the lumber home, by then we had a small farm. My "job" that summer was to pull the nails and straighten, putting them into a coffee can. piling up boards that were true 2x12's that were 16 foot long. Dad somehow found old telephone poles and we used them for posts for a Lean-to for farm equipment.
True to my upbringing, while working in a factory, the company purchased new equipment and was shipped in long lumber. I convinced them to let me take it, instead of the landfill. so back at it again pulling out the nails and keeping them, for construction of a shed that I had built. Now my Son has picked up the trait as well, and maybe in a few years, my Grandsons too. Funny that I read this thread this morning, because a car dealership in a town I was in yesterday bought an old Motel, and was tearing it down, hauling it to the landfill. Sad.