It's not a Disney vacation without tears!

So my wife has this motto from her childhood "It's not a Disney vacation if there aren't tears!". Now, in my family we do not have this saying, but since she said it I've heard a few people also saying the same thing. Maybe it's something about the Florida heat and the crowds that cause melt downs? Can anyone please explain this to me?!??!

Enjoy this awesome family shot from wonderful Animal Kingdom!