Professor Elizabeth Loftus of the University of California, Irvine, is one of the country’s recognized experts on memory. Her Ted Talk on false memories is a must-watch for every analyst trying to chart the public’s reactions to both Donald Trump’s recollections of the aftermath of 9/11 and to former Secretary of State Hillary Clinton’s claims of coming under sniper fire in the Balkans or of having explored joining the United States Marine Corps as a young lawyer in Arkansas.

Memories cannot usually be “fact checked.” The exception is when those memories have been differently stated by the same person at different times. People remember what they remember, and often they “remember” that which did not actually occur. That is the point of Professor Loftus’ work. It is why I cited her on “Meet the Press” Sunday. My guess is that pretty much everyone has some false memories which they believe to be true.