OK, here they are. Cluttering is not as bad as hoarding, and these days I'm realizing I am a clutterer, not a hoarder. Still these thoughts I have found helpful. These are paraphrased from a webpage; I can't remember now which one.

Simplified Hoarding is about the fear of throwing something away that you might need someday, of not being able to remember it perfectly or that if thrown away it will cause a problem or that something bad may happen.
MISCONCEPTION: The moment I discard this item I discard a part of myself.
MISCONCEPTION: The moment I decide to throw something away I may be making the wrong choice.
MISCONCEPTION: The moment I am unable to know how to categorize an item, I will place it in sight so I will know where it is.
MISCONCEPTION: The moment my object has a use, I have to keep/use it so it doesn't get wasted.
MISCONCEPTION: The moment you decide to throw something away, you no longer are the person in control and what happens to this item will be in the hands of others.
MISCONCEPTION: The moment you throw something away, you may forget its content or the way it looked and it will be gone forever.

(fear of letting go, of moving on.)
Letting go of things in life is so needed if we want to experience some sense of freedom.

MISCONCEPTION: The moment you throw something away, you let go of that specific part of your life, however insignificant it may be.