Why does change exist ?

[Massimo]

Why doesn't everything just stay the same instead and why is this impossible ?

[Darth_aurelius]

Why doesn't everything just stay the same instead and why is this impossible ?

The short answer is that the governing laws of the universe are modulated by the entropic principle which yields loss of heat, an every evolving cosmic landscape and necessitates change. The long answer relies on physics which are beyond my cognitive capacity to intelligibly render or explain to you here.