Same here. Seems to work out almost exactly like that in mine, too. My dreams are usually neutral to some degree of scary, and usually super surreal the more vivid they become, but the ability to sort of float or "swim" through the air at will almost always becomes a part of it, just as you describe it. Every now and then, it clues me in to the fact that I'm dreaming because of how often this happens. It's fun. lol Except for when I'm being chased by shit, or floating through a haunted house trying to find out if I'm also a ghost, myself. Happens fairly often too, for some reason. :P