Re: They ought to teach this in schools.
It however appears to be in Chubb's best interest NOT to publish the post-mortem since the reason is probably something on the lines of what you wrote there, and admitting this schoolboy error would result in not retaining a customer such as you and many others.
The catch is: "Where do you go then?" Seems every insurance company is getting hit by stupidiy, usually hacked but this one is different. Still... they've all (for the most part) been named and shamed and with no apparent flashback to the bottom line or customer numbers.