My friends would never ask to borrow my bags because they're aware of how much I treasure them (never putting them on floor, etc) and would be paranoid about scuffing them/dropping wine etc on them. They would never put me in the position of trying to refuse politely.
I did realise that I would never use a Mulberry Araline which I had bought a couple of years ago so I gave it to a friend whom I knew it would suit. She uses it, I didn't. It's not part of me any more and I don't think about it. However, I do have far too many bags and they're going to have to be pared down. Those which remain will be for me (and, eventually, my daughters) - not for anyone else. I'm not being selfish, I think; my bags are my own indulgence and I love and bought them after a lot of thought. Others can do the same.
I truly agree. It is not about being selfish or materialistic at all. It is all about caring and protecting part of our self.