Not exactly, but our representation of what's behind us is a lot more sparse than we would assume. That is, I might not be surprised by what I see when I turn around, but it could have changed pretty radically since I last looked, and I might not notice. In fact, an observer might be quite surprised that I missed the change.

Objectively, Simons and Chabris (and many others) have a lot of data to support these ideas. Subjectively, I can say that these types of tasks (inattentional blindness, change blindness, etc.) are humbling.