I've never been totally comfortable with calling the administrative user "root", not because of prior Windows experience, but because, well, in our slang "root" means "to have sex with".
Thus, in Australia you may hear somebody described as a "wombat" because he "eats, roots and leaves". Our slang is so damn subtle.
User: The book says I need to be root?
Me: **snigger** Yeah, root.
I am so damn juvenile.