From ignoring a relative you notice having a few too many drinks at every family function to not even thinking about the threat of being struck by a meteorite, everyone operates at a level of obliviousness to the world around them. But that's normal, says University of Minnesota Family Social Science professor Paul Rosenblatt. In his new book, "Shared Obliviousness in Family Systems," Rosenblatt explores this intriguing subject and says while a certain amount of obliviousness is necessary, it can also lead to trouble.