Everything around is changing. Surroundings are changing E.g. Mountains are growing / shrinking, rivers are flowing. Body is changing E.g. every cell in the body has died and been replaced. Thoughts are changing E.g. likes / dislikes are changing, beliefs are changing. Life is moving towards death and from death springs new life.
At the first sight it seems that 'Change is the only constant'. However it is superficial. Looking deeper there is a subtle constant that is missed.
My surroundings are changing. My body is changing. My thoughts are changing. Things are happening to me. I am doing these things. This is mine. This is not mine. Everything is happening with I/Me constant as the background.
I/Me constant appears first. Then everything else. Nothing exists without this constant.