Nothing ever remains the same; everything is changing all the time. Evolution is a constant in all things whether it is an inanimate object of a physical being.
Think of it in terms of a stagnant pond. The longer the water sits the more bacteria grows and the molecular composition of the pond continues to change. Since everything is made of energy and under a super powered microscope you would be able to see that the difference in a something that is “solid” and something that is not is the spacing of molecules/matter.
Other ways you can accept or understand this law is to think of time or even the compounding effect of interest. Time never stops or slows down, EVER! It simply remains constantly changing. I like looking at it in terms of compound interest, being business minded it is motivating to me. Try this think of the way you save money or would like to save money. Being that you know that time is going on and on never stopping and you also know that every minute you money is in the bank it is gaining interest, however small it may be that, that is just a little more proof of change is a constant.