Yes precisely.....
I go by the name with the initials of my username on here SWK.
My first name is Stephanie [real name] but i changed it around a little to something different. My middle name is the middle name of one of my uncle's [who died when he was a baby]. My Last name is now my [real] middle name.
So you see, you wanting to use your middle as your last is fine. Angelina Jolie is really just [Jolie] her middle name. She decided not to use her real last name, [Voight] [daught of Jon Voight] so that she could make a name for herself, and not be looked on as the daughter of Jon Voight. My reason is simply that i hate my last name, no one can pronounce it or spell it correctly. Of course, now i have the same problem with my new first name.
But hey, can't have everything.
SWK78