Mac OS9 was the first system I used, many years after my beloved Commodore 64.
From 1990 till 2001 I didn't own nor did I use a computer.
Then a friend gave me an old Apple PPC with OS9 installed on.
It took me very little time to get familiar with the system, before that I hadn't even used a mouse
A short time later I got acquainted with Windows as well and it struck me that, although the PC on which Windows 98 was installed was faster and had more video memory to watch video content etc., the Windows working space itself I didn't particularly like.
It was closed, somewhat claustrofobic, it set a path for me to walk and made very clear where to stop, which areas (system folders) were forbidden etc.
The overall open structure and atmosphere of OS9, (atmosphere? it sounds silly I know) I liked much better, so much better that I could live with compatibility issues and the lack of games for instance.