You're right, but I think you miss the point of this article.
The point is that one could store in his brain all the information needed to pay and receive any amount of money, without needing any extra storage device.
Because this money is Bitcoins, and because they are not stored anywhere, it technically means that all your money, all your wealth, resides in your brain - hence the title "Brainwallet".
This is a fascinating thought experiment, but not an assessment of the most secure way to store money.
The point is that one could store in his brain all the information needed to pay and receive any amount of money, without needing any extra storage device.
Because this money is Bitcoins, and because they are not stored anywhere, it technically means that all your money, all your wealth, resides in your brain - hence the title "Brainwallet".
This is a fascinating thought experiment, but not an assessment of the most secure way to store money.