A fun artifact of deleting your facebook account is that all of your comments get deleted (hidden, I guess, is more accurate) too, which means that in old threads people who interacted with you now appear to be interacting with themselves.

My friend had a profile picture in which he was doing something silly with his eyebrows. I commented "Nice eyebrows" and he replied "You're just jealous." I've since deleted my account and now there is only one comment on this profile picture, by the person the picture is of, reading "You're just jealous."