Here's why:

* Energy is the ability to do work. Work can be done on non-living things, like moving a rock or heating a piece of metal.

* Everything in the universe has energy. Even objects at rest possess energy in the form of potential energy. For example, a rock sitting on a hill has gravitational potential energy due to its position.

* Energy can be transferred and transformed. This is true for both living and non-living things. For example, the sun transfers energy to the earth as light and heat, and this energy can be used to power a solar panel (a non-living thing).

Living things are unique in that they:

* Use energy to maintain their internal processes. This includes processes like growth, repair, and reproduction.

* Obtain energy from their environment. This is done through processes like photosynthesis (for plants) or consuming other organisms (for animals).

* Release energy as waste. This is done through processes like respiration and excretion.

While living things are very much tied to the concept of energy, energy itself is not limited to them. It's a fundamental concept that governs everything in the universe.