How can you not notice that? Hate it or not it is incredibly easy to notice.

It's trivial to notice when you go looking for it. But if you keep your machine in dark mode and don't use apps with an overloaded menu bar, it's also very easy for the notch to entirely disappear from your awareness.

Same here. I actually had to look up whether my model had it since I'm not in front of it.

I do use external screens a lot tho (in addition to the built in one).