It's hard to believe, but it's true - Shania Twain suffers from stage fright. 

She told James Corden on The Late Late Show that the problem started in high school, when she was asked to sing one of her original songs. When she stood up, she was so nervous that she peed. Not just a trickle, but a full-on puddle. Fortunately, she was wearing a skirt and had a glass of water on the floor which she quickly kicked over to cover the puddle. 

Nobody was the wiser. Until now.