Being on the other side of planet in the middle of a desert, I just might have a good guess. The cache of items I have found have been, I beleive, due to pirates, thieves or raiding hordes of mongols. People here have hidden them in order to protect them.

Hidden treasure implies future consumption. I don't see pirates delaying gratification so they can have a better future. They would only hide it if they wanted to protect it; so the treasure story better involve, storms and/ or Spanish or British ships hunting them down.

Good Luck, There are treasures out there!

Tim