Feet are strange - at least mine are. I have a pair of expensive (for me) shoes that I bought 5 or 6 years ago. I've been very careful with them so they wouldn't wear out, but I can no longer wear them. I was over 200 pounds when I bought them & they were size 8 1/2. Now the rest of me is smaller, but I'm wearing size 9. I can't get my feet into the 8 1/2 any more.

Perhaps it's age? I know feet can spread out during pregnancy, but that was 25 years ago. If menopause has the same effect, that was also some years ago - 8-10 years.