I recently took a class where a central theme of the class was the idea of entropy. Entropy is the second law of thermodynamics which helps explain how things like pans cool down and how companies die. Energy disperses throughout the proverbial system as time goes on.
Think of DNA. The DNA in your body is being copied over and over. Mistakes are made from time to time so, over time, the quality of the copy deteriorates. Think of a hot pan fresh off the stove. The heat is generated from the vibrations of the atoms. That vibrating is not perfectly transferred to other atoms through so eventually, the vibrating dies down and the pan slowly cools.