The life I have led in other countries, the clothes I wear when I am in the office, the people I interact with on a daily basis, the friends I made outside my home town, do not exist except through our email/phone/in person conversations. They are as real to her as characters in a book. That's why I can have a shirt I've owned for five years and she can see me wear it and say, "Oh, is that a new shirt, I've never seen it before." I own a lot of clothes she has never seen before, but to her they do not exist until she has seen them, until she has interacted with them.
When she told me who I should invite to my baby shower she included people I had not seen or interacted with in 10-20 years. They were important to her. She had interacted with them recently and I had known them in my childhood so they must also be important to me.
I think many of our hoarders are playing one player video games (this concept was mentioned in someone else's post on COH group, I think it is spot on). They are the center of the universe and when you leave their sphere of influence you get paused (in their minds). That's why their perception of you, your likes, dislikes, friends, clothes, everything is essentially paused as a teen or younger depending how independent you were of them at what age. Kind of like that old program where the kids were placed into tupperware containers to keep them safe, if you were paused no harm would come to you, you didn't get exposed to your father's craziness, you didn't go off to a foreign country and get felt up on a bus, you didn't take chances that made them uncomfortable, you were safely paused and in a safe place.
Just my thoughts.