Why metaphors are the most powerful literary device?

The fundamental way in which knowledge works is building up on already accepted facts. To understand the solar system, you first need to understand the concepts of planets and the sun and the orbits. To understand planets, you need to start with the earth. If you go down deep enough, you will arrive at undisputable truths that you have to agree with to further understand bigger concepts. The solar system makes sense only if you accept that the earth is round as are all the other planets.

Theory alone can only go so far, if you throw in a bunch of undisputable examples that follow that theory, you have a watertight argument in your hands.

Metaphors essentially parallel this "theory - example" paradigm and connect meanings among examples of seemingly disconnected things.

Jack was thirsty. Jack's throat was dry. Jack hadn't drank a single drop of water in 7 hours.

VS

Jack was parched like the earth, yearning for the first hint of rain.

Metaphors work as well they do also because of the inherent use of the reader's own imagination in the process of conveying the idea. Humans have an incredible ability to be amazed by their own minds.

This is my running list of my favourite metaphors I have ever come across.