I'm planning on changing it all. My father was a jerk and a thief, my mother and her father are not a great part of my life, and it wouldn't feel right having my grandparent's name, somehow. I was initially going to take my mother's maiden name, but recent events have changed my mind and I took what would've been my second middle name and it's going to be my last. (I've been planning on changing my name my whole life for those reasons.)