Heraclitus, said the professor, was a Greek who wrote, “You can’t step into the same river twice…” Why would anyone step into a river? said Blurtso, that’s what bridges are for. You can’t step into the same river, continued the professor, because the river is always changing, and when you step in a second time, it’s a different river, and you are changing too, and are not the same as when you first stepped in. In fact, repetition is a myth, it’s impossible… I’m sorry, said Blurtso, I’m afraid I wasn’t listening, could you repeat that?