You're starting to sound like my OH, who is an electrical engineer.
When he was attaching some nice glass shades I'd got to a new fitment on the kitchen ceiling, I was watching him - and he didn't earth it.
I asked him about that, pointing out that the instruction sheet said it had to be earthed.
He just said; "
I know it's not earthed, so it doesn't matter."

"Besides", he added, "the instruction sheet is just somebody else's opinion about how to do it."
