A person may plan as much as he wants to, but nothing of consequence is likely to come of it until the magician Circumstance steps in and takes the matter off his hands….Circumstance is powerful, but it cannot work alone; it has to have a partner. Its partner is man’s temperament–his natural disposition. His temperament is not his invention, it is born in him….A circumstance that will coerce one man will have no effect upon a man of a different temperament.

“[Take] poor Columbus. He elaborated a deep plan to find a new route to an old country. Circumstance revised his plan for him, and he found a new world. And he gets the credit of it to this day. He hadn’t anything to do with it.”

– Mark Twain, “The Turning-Point of My Life,” in WHAT IS MAN? AND OTHER ESSAYS