Herman Cain joins a long list of embarrassing brain freeze moments caught on tape when he paused to answer a question about him agreeing with President Obama on Libya.
We all know about Rick Perry's debate disaster when he couldn't remember the third federal department he would cut if he became president.
Arizona Governor Jan Brewer had a similar moment in a debate last year when she couldn't put the words together for her response to a question. It got so bad, she could only laugh.
One teen suffered a brain freeze right in the middle of singing "The Star Spangled Banner."
What's going on?
T.J. Walker, Media Expert at The Daily National, told INSIDE EDITION, "Public speaking is the number one fear people have, and when you're in front of people and in front of a camera, the brain shuts down."
Former President George W. Bush experienced it as he searched for the words to that old adage, 'Fool me once, shame on you. Fool me twice, shame on me.'
Bush's mangled version was: "Fool me once, shame on....shame on you. Fool me, you can't get fooled again."
So the Republican presidential candidates should take comfort in the knowledge that their brain freezes, no matter how embarrassing, are a common human experience.