Eddy Harris's opinion is that if life is full of only happiness, you have nothing worse to compare to. It's like over listening to a song you love, eventually you loose intrest because you've heard it so many times. Life needs to be a mix of emotions, because if you're always only happy, you're missing out on the rest of life. This saying could also be changed to reflect the other side of this, to be something like "If you only get rain, eventually all that's left is a flood." Mix things up in your life, or you'll never get to fully experiance it.
