Yeah, I think we're all guilty of it if we're honest. You can't be too hard on yourself about it, though -- unless you start saying things like, "Gee, Jane, it was really nice to see you again. A shame you've turned into such a fat, gray-headed slob."
People put WAY too much emphasis on external beauty, but that's the world in which we live. I've met some truly beautiful people who weren't much to look at and also some incredibly good-looking people whose hearts were blacker than coal.