IMO not a good sign, or possibly you are both zen masters. My wife and I argue occassionally, but we argue well (almost always ;-)). Meaning we stay on the subject, stay in the present, and most importantly don't make personal attacks. Neither of us likes to lose, but by following these rules we can argue about subjects without it ever being about "us."

Not just by the way. I'm a very private person who needs time alone. It is just the way I am (my wife wonders if maybe I'm a little autistic). She understands and respects that. So you can have quiet and alone time AND a live in partner...if you have a partner that accepts that is part of the deal with you. Just make sure she knows that before she moves in.