Last one I remember was related to the keychain update, you had to re-acknowledge all of the maintainers in the arch-keyring.

It was a lot of work to visit them all and get them to recite their key signatures while I held their hand to make sure they were really there. The blood tests took a while to come back and affirm their identities, but it was worth it for the piece of mind.

Easier to start with the plain truth, something you can see with your own eyes, and work your way to the subtler arguments.

https://archive.org/details/earth_not_a_globe_review_1893-1897_201804/mode/1up