This is an outstanding article.

There's a non-zero probability that they get it on the first try.

They use the midpoint (50%) as an estimator. This is just the expected cost.

I know, just a scary thought, roughly about the odds of me existing.

Actually, thinking about it, there's more entropy in my DNA than your password, and we've not even got to the Earth existing, yet here I am.

And because somebody inevitably has to: https://xkcd.com/538/

More information is more entropy. A novel has more entropy than a haiku. You are a password that took 13.7 billion years to crack. Expensive there you are.

funny to play around with!