It's usually when I find a good "cause". I've been de-stashing for the past few weeks because I've been helping make Christmas stockings for the troops. I've gotten to use up a lot of Christmas fabric, denim, home decor, thin wale corduroy and other assorted fabrics. Hundreds of yards later I'm beginning to see a difference in my stash.
Xenodeno---you might want to hang onto that older fabric for at least a few years. Tastes change.