Why does my 10 year old cat drag around my husband's socks and meow desperately?

My cat had one litter of kittens 7 years ago. Recently, she would go into our room and take my husband’s clean socks. She will carry it around, and usually stops in our kitchen. She will meow as if she were in heat. (She’s fixed) We have no idea why she does this, but it happens at least a couple times a week. We think she is having flashbacks from when she actually did have kittens. But we’re not sure. Anyone know why she’s acting so strange??