Patronizing patriarchy!

So, the other day, my "husband" (read: common law spouse) and I were buying something at a store. As there were none of the desired item in stock, the store had to mail it to us. Annoying, but whatever. The male cashier started taking down our info and this is the conversation that ensued:

Cashier: Name?
Me: I'll give you his name 'cause we were using his credit card
Cashier: Ok
Me: Abc. Xyz
Cashier: Actually, how 'bout I get both of your names?
Me: Ok. Sarah
Cashier: (interrupting) Xyz.

Me: Uh (pause) Sure.
Cashier: Oh, I know what that means...

Really, sir? Do you REALLY know what that means? Do you know that it means that I decided not to correct your assumption that we are a) married, and b) that I took his name? Do you know that you assumed that I obliged the expectation that I would give up MY birth name and take on HIS? Do you really know what that means?

I am not an Xyz and, to be honest, I never will be (married or not). However, I pick my battles; it's just easier for me to say 'sure' than to say "Well, no. My last name is different."

Of all the ways the patriarchy is manifested in my society, the patrilineal system is at the top of my list of irritants. When I was 3 years old, I found out that my grandmother had had her married name longer than her birth name. I was appalled! The story is that I yelled "What?! No man is going to take MY name away from ME!" I have never wavered from that conviction.

The expectation that I should or would bothers me. Why would I give up the name that my parents gave me? Imagine me being Mrs. Abc Xzy. What would that say about my identity? My individuality? My independence? That would make me an extension of him, like his child. Why is that expectation ok?

No, thanks. I don't want to be the property of my husband. I don't want to be an extension of him. Although I carry the name of my father, and thus, am an extension of him, I like my name; it was given to me at birth and I will never change it.

I was curious to find out why women change their last names when they marry and when it started. After some half-hearted web research, this is the only thing that I found that addressed it directly. I have no faith in this source, but it's something. It attributes the origin of name-changing to the Bible. What doesn't originate from the Bible!? (Stay tuned for the standard of Christianity). Ugh.