I haven’t tried juggling for decades but I did manage to teach myself basic three-ball juggling when I was at university (any excuse to avoid revising!)

I think it took me a couple of weeks though. I’m a bit malcoordinated for that sort of thing in general. I think you’re right that there’s some sort of natural aptitude that not everybody has. Fortunately basic juggling is just about easy enough that almost any idiot can do it.