“Cannot Unsee”

Serious question (and partial rant).

What exactly does it mean when someone says “I’ve seen it and can never unsee it”?

I’m resisting the urge to be snarky and ask if it persists when their eyes are closed like it’s burned into their cornea (similar to viewing a solar eclipse without protection). And I understand (somewhat) if someone is referring to a flaw in a specific watch they own or are qc’ing.

But it’s being used to refer generally to makes/models of watches, most recently the CF Explorer I (3 and 9).

If I have a CF E1, there’s absolutely no way a person can see whether the 3 & 9 have that specific flaw without close inspection (cannot be seen on the wrist). Do they still see the flaw even if it doesn’t exist since they can’t unsee it? 😉