Metaphors are everywhere, in everyone’s speech. Sometimes we do not even recognize that we’ve just created a metaphor. They are vivid parts of our speech. Can’t image our life/speech without them. Metaphor, it's safe to say, is the bread and butter of literature. I think the reason why metaphors exist and are created because human beings have rich imagination, vision and ability to see similarity between different things. Because of this ability, we make other people laugh or wonder. Overused metaphors become trite. Metaphors really open up the meaning of a phrase. They give us a new and exciting and creative way to say or see something. Thank God, they exist.
Metaphors are different from similes because metaphors leave out the words "like" or "as." For example, a simile would be, "You're like a toad" or "You're like a star." Metaphor is: “you are a star”, “you are a toad”. We can easily differentiate them. (Although, technically speaking, similes are a type of metaphor.) Pop music gives us lots of easy examples. Just listen and recognize.