Sam, do you understand what is meant by "the hand that rocks the cradle"? Do you understand what "rocks the world" means? The latter can have two meanings that I can think of:
1) It takes care of the world like a mother takes care of her child
2) It creates a lot of commotion and notice ("This is going to rock your world!")
Which meaning do you think is meant? Is there another meaning you can come up with?