From: Ruby Freak Date: 2008-09-23T13:05:09+09:00 Subject: To be not, or not to be not? That is not the question Code in question: module AuthenticatedSystem protected # Returns true or false if the user is logged in. # Preloads @current_user with the user model if they're logged in. def logged_in? !!current_user end ... Is !! as simple as it looks, or does it have meaning beyond a double negative? Google doesn't recognize !! in a search. I see it as "Not (current_user == Nil)" ...