We don't always know what we are saying

People's conscious awareness of their speech often comes after they've spoken, not before.
"So cognitive scientist Andreas Lind and his colleagues at Lund University in Sweden wanted to see what would happen if someone said one word, but heard themselves saying another. “If we use auditory feedback to compare what we say with a well-specified intention, then any mismatch should be quickly detected,” he says. “But if the feedback is instead a powerful factor in a dynamic, interpretative process, then the manipulation could go undetected.”"