Perpetual alteration is the essence of the perceptual universe. A thought springs up in your head and half a second later, it is gone. In comes another one, and that is gone too. A sound strikes your ears and then silence. People come into your life and they leave again.
Friends go, relatives die.
Your fortunes go up and they go down. Sometimes you win and just as often you lose. No two moments ever the same. There is not a thing wrong with this. It is the nature of the universe.