[pixelesque]

I remember early OS X (10.4 / 10.5? - damn, that was 20 years ago?!) with a laptop and external monitor.

It was farcical, as the menu bar was always only on the primary monitor, so you had to use/click menus on that monitor, even if the actual window the menu was for was on the other monitor.

Around 10.7 or so they started putting menus on both monitors at the same time to at least make this scenario a bit more sane.