Those ubiquitous plastic bags. Nearly everyone saves them. And they do come in handy. But people who suffer from hoarding disorder usually have far more they they would ever need in a lifetime, and they don't want to let them go.
Unless...they are moved by a good reason to.
When I told one of my clients who has hoarding disorder that I have another client whose elderly husband is infirm and they go through many plastic bags each day for reasons of hygiene and always need more, without hesitation he collected three piles of them and handed them over, without question, without delay, without a second thought.