He probably had the mistaken idea that this would save them at least some of his possessions.
But now she could see how mistaken that idea was.
I had the mistaken idea that you people up here were better than we were.
"I came to let you know your staff has a mistaken idea about my reason for being here," she informed him haughtily.
This is not the first time journalists have shown mistaken ideas of the media of the past.
So far as your other things go, you have a badly mistaken idea about viruses.
Both had been hunting for me with the mistaken idea that I was a menace to society.
I'm afraid you've got rather a - well, a mistaken idea of Madame.
Then I think there are lots of mistaken ideas going round.