He is talking out of the back of his head ! What he says is so obviously not the case. (Google)
He was, of course, talking out of the back of his head. When you come to understand how Naperian Logarithms work, and gain an understanding of the Poisson Distribution, then you won't be fooled. (Google)
I also told her I might be talking out of the back of my head and that I wouldn't be offended if she ignored everything I said. (Google)