I think some people use the controlling of things to control people.
My older sister used to focus on things of mine she wanted, from our teens to adulthood. Usually things of mine I liked which she coveted. She would grind me down to have things until I caved in as she had a very bullish nature. It went on our whole life, from a lovely woven basket I had for my craft GCSE to store my haberdashery, (loaned, never seen again), my first and only pair of gold earrings (lost) to books, clothes, a variety of stuff.
If I had anything really lovely, she really focussed on that. I had a beautiful dress once which I wore to a wedding bought for me our mum. She borrowed it and never to returned it, despite me asking and wore it to a number of significant family events, even my own graduation and I have so many photos of her wearing my things.
If she stayed with me, she would ask to borrow clothes and I'd say ok but name things she could not take as I knew it would be months before I saw them. She would still take them.
However, things were returned so trashed ( the dress, unwearable) or not at all - she had given them away to other people or threw them way
MyBooks were never ever returned, lost. All these things were laughed off as not important, oh that old thing etc. 
Sometimes we would clash and I felt I couldn't fall out with her because I wanted my stuff back. Years later, we are now NC and she doesn't have any of my stuff 
Things can be used to control people. Do not let your stuff be taken, and the return or non return ( and any emotional attachment) be used to control you.