I'm actually surprised how many arrow key people still exits, I thought I was one of the few.
I never made the change as we were stuck using a dx2/66 up till 1998. Duke3d was about the newest 3D game I could play which doesn't really need a mouse as the gun autoaims above/below you.
So i missed out on those 4 years of people playing truly 3d games like Quake and Unreal and starting to use the mouse. I did play a bit of Unreal and Quake 3 with work colleagues after 98 but I'd had the arrow keys burned into my mind by then.