Because we knew what it was to have to do with out, so you got in to the habit of saving useful things.
Bette to have it and not need it, than to need it and not have it.

My Grand children call me a hoarder, because I throw very little away and when I do it is usually recycled.
When they ask why, I always have the same answer, "because one day I might need one."
Sure enough, all four of them and their parents have to come to me at one time or another asking "Granddad have you got a ..." and I am always able to say yes.