Some say that it shakes their body. Some say that it fills them with calm seas. What is it? Some say that it feels like electricity coursing through their body. Some say it feels like Chi or prana. What is it? Some say it feels like the first time that they fell in love. Some say it feels like they're in an erotic trance. What is it? Some say it happens when they're in this position or that. Some say it can happen anywhere and at any time, with or...