Our New Year's projects often involve refitting closets, since the Container Store has a great sale on Elfa closet components. This year it was MY closet's turn, and it's so good to see everything neat and organized, and the three huge bags of good stuff I don't or can't use any more will do someone else some good. I've seen hoarding, and it's not pretty - it really is a mental disorder - and I'm determined to be as opposite to that as I can be!
I've seen it a couple of times in elderly ladies in the neighborhood. Part of it I assumed was that they grew up in extreme poverty and you didn't throw out ANYTHING that could be re-used.
My grandmother quilted and never ever ever threw away any piece of fabric, even if it was no bigger than a saucer. It could be used later!
Another lady had stacks of styrofoam meat trays, boxes of bottles, stacks of newspapers etc. Good news was it was organized, back news was her garbage can rarely had anything in it. So about once a month her granddaughters would go over while she was at a Dr's appointment and declutter as much as they dared.
She always noticed though ;)