You heard when you were kid- no two people are exactly alike- not even twins. No two snowflakes- I took their word since it never snows here.
Then you get into science...chaos,butterfly wings...no two waves of the ocean - all the countless ones formed all the time,are never EXACTLY alike. Nothing is. From one end of the universe to the other waves can be damn close..but never the same perfectly.
I'm sure we one day will find not even atoms are exactly alike if you could get down to the size..one's electrons wizzing around and another atom are like two clouds on earth- look the same,but are not.
Close,but not even two things in this entire Universe and maybe multiple Universes..are never the same.