Stuff I didn’t know: Earth’s rotation affects the accuracy of long-range shells

I didn’t know that the Earth’s rotation tends to deflect long-range artillery shells. More here. It is called "the Coriolis drift," which sounds to me like a good movie title.

I learned this while reading to try to understand why the Coriolis effect makes wind bend to the east in the northern hemisphere and to the west in the southern one. (And has a similar effect on the artillery shells — if you fire it 75 miles straight to the north from Paris, it will hit to the east of where you aimed.) But I still don’t understand why the effect is different in the two hemispheres. I was bad at geometry, so I suspect it is that I lack spatial imagination.