A number of years ago, when our house burned, I was the recipient of bags of clothing destined for donation to our local ministry. At first it was hard for me to not keep everything that was my size. But after a few days I realized that if it was something I would never wear then keeping it wasn't right and I should pass it to someone who would gratefully use it.
I now apply that to my fabric and craft supplies as well and from time to time will go through and weed out what I know I won't use. Need to do that soon with my yarn stash. I have a friend who would gladly use it for her hats.