Hoarding and Compulsive Buying.

I do not know one person who is aware and present and hoards and clutters at the same time. It's like smoking. You cannot do it when you are aware and present.
All meditators I know are extremely well organized persons who have few possessions (counts for me too).

 My favorite nun: Ayya Khema

 Ayya Khema's room

 

Both smoking, and hoarding & excessive cluttering are listed under Compulsive Disorders in the DSM. This led me to think that hoarding is a kind of addiction, that is, something goes wrong in the reward system of the brain. The same counts for compulsive buying (of things you do not need). There's a high involved in all of these behaviors; the high of acquiring, and owning. Just like the tobacco high or the heroine high coming down from it is quite painful and leads to the next high.
Only a deep level of awareness can heal the hoarder, who is often quite powerless in the face of her/his own behavior.
Often there is an identification with stuff in order to feel safe.
Only the deep realisation that we can feel safe in the face of great unsafety (the realisation that we all die alone) can heal the hoarder. Truth seeking through insight meditation (Vippassana) is helpful to reach this realisation.

Typical hoarder's room