I need answers!

Why is it that babies cry and cry and cry before they fall asleep? And why is it that while they are trying really hard NOT to fall asleep, but they do and the crying stops, when they realize that they have fallen asleep, they wake up and cry some more?

Also, why does this (Japanese crying baby contest) even exist?

"The event first began in 1993 to pray for the health of babies. Men wearing mawashi sumo belts gently shook the babies in a bid to see how powerfully they could cry. A Japanese proverb says that babies who often cry will grow up to be healthy."

They Shake the babies????!!!