Let's list everyone's worst nightmares: falling, someone hurting a loved one and standing up in front of hundreds of people bare naked. Professional pianist Maria Joao Pires came close (and she would have much preferred to have been bare naked).

She prepared the wrong piece for a major concert and didn't realize until the first note of the live performance! The look on her face gives ME stomach cramps!
What would you do? The concert has already started and you have to confess you practiced the wrong song! You're totally unprepared in front of an entire audience.

Well, you won't believe what Maria does. Watch the video to see.

This was possible because she had memorized the piece previously. Unbelievable. Nerves of steel. I looked up mettle in the dictionary and it said, "Adjective; Maria Joao Pires."