Re: Mostly
"written copy in an old-fashioned notebook in the same old-fashioned pocket or handbag where you keep your plastic."
Well , I'm not against writing passwords on paper in your house , in a drawer. This means every hacker in the world cannot access them without coming to your house, which they tend to draw the line at.
However " the same old-fashioned pocket or handbag where you keep your plastic. " sounds like its going to travel every place that you do and could get lost at any minute in a public place . Or worse , stolen.
Therefore this is a bad idea for the same reasons its a bad idea to write your pin on your plastic