Because Becky asked.
The day after we got married, my husband and I opened a joint bank account. A week after we got back from our honeymoon, I queued up at the Social Security Administration office and changed my last name.
Now, I am a feminist of the old-school, second-generation type. I think it is moronic that women feel obligated to change their names and that so many men simply expect it of them. I am offended by the name “Mrs. J Rosenbaum,” both because it is patriarchal and because it is inaccurate. My name is not J – that is my husband’s name. (While we are on the subject, I have a Ph.D., so I ought to be referred to as “Dr. Emily Rosenbaum” if we are getting all formal and correct, although I prefer simply “Ms.”)
But, I changed my name in an awfully big hurry. My rationale? My maiden name was my father’s name. Either way, I was going to have a man’s name. Might as well at least have a man I like.