Yup. My mom, my wife, my wife's mom, my mom's mom, my brother's wife, both of my aunts, both of my female cousins, the one high school friend I keep in touch with.

I think that's why so many "security" systems consider knowing your mother's maiden name a piece of the evidence to "prove" your identity. If changing the middle name to be the former surname was more common, that would be even less secure than it is now. :-)