It's not easy to pat your head and rub your stomach at the same time. It's not easy learning how to juggle.
However, if you want a real challenge of co-ordination, try guiding two silver balls simultaneously along two twisting paths filled with obstacles, pitfalls, and other hazards.
If you want to see what that feat looks like, check out our hands-on video of Dual Survivor. Watch in detached amusement as I tear my hair out trying to progress past level six of this insanely challenging game of skill.