Getting further and further into the weeds of Windows 95/98/2000/ME. There are so many crazy features and options I sincerely never knew about but have found on accident/reference manuals. My favorite one today: moving and resizing windows with arrow keys (ctrl+arrow for pixel adj), as well as snapping window position to where your cursor is (if your window titlebar gets stuck offscreen this is particularly helpful).
Of course implementing these features is a whole other ordeal.