Heraclitus notion:

You are always different, and the river is always different!

This means:

1. You can keep repeating the same thing over and over again, and not repeat yourself, because you and the circumstances will always be different.
2. In photography it is impossible to repeat yourself, even if you shoot the same places over and over again. The photons of light will always be different. Even the subjects you photograph, they are always aging (slowly dying), and the molecules of the world, others, and yourself is always changing.

Thus in photography: you never photograph the same thing twice (your subject and yourself is always different!)