I always took for granted that my name would be mine forever.

I am from a place (Quebec) where women keep their last name by law (since 1980 or so). Socially you can call yourself whatever you like, but as far as contracting, government relations (driver's licence, medicare...), banking, etc. one has to use the name printed on one's birth certificate. If you really want to change your name, you can go through name-changing procedures like everybody else (example: if you name is Maria and you would like to be called Barbara instead), posting ads in the newspapers, paying some legal fees, going to a notary, something like that, and then you get a new birth certificate. Few people do that, and I know no woman of my generation and few women of my mother's generation who call themselves by their husband's name even socially. Kids are called by one or both parents' name, and nobody is surprised if there are two or more family names running in the same family.

Really, if Joe Smith has three kids by the name of Smith in his car, I hope the border guard will not just wave him through without checking the paperwork because they have the same last name and therefore Joe must be the father.

When I married to an Anglo Canadian, I think his family (and probably him, too) would have been happy if I had changed my name but they knew that was not going to happen. Furthermore, I love my last name, and I am a published professional in my field, it would not be smart to change my name. I don't know yet what we'll do when we have kids. Our names sound cute together, so I guess we might go that route.