My problem is letting go of stuff, getting better, but not great yet.
I have struggled with this for a long time... it runs in the family.
That and I get really sentimental about certain things. I have gotten a lot better about it though. About twice a year we completely purge and I would say over the last two years we have gotten rid of probably half of our belongings. (And over half of my shoes and clothes which was a huge step...
)