That's the clue - you never repeat the same activity exactly the same way.

Seemingly identical action, from the performer's point of view, is performed in a different environment each time it is repeated. Unless you are the Laplace's Daemon, you can't say for sure you repeat the same action over and over because the environment could change in the meantime in an unimaginable way, and that could influence the outcome.

I just really hate that quote because it is detached from reality.