Some people are "slick" while others aren't. Same goes for surgeons. Same goes for nurses. Same goes for the guy pushing the mop on the floor.
It think this has to do more with genes than it does training. Some people indeed to just have natural ability, whatever that means exactly. Most people who played sports or are very good at video games since being a kid I think have a huge leg-up on manual procedural skills over their colleagues who didn't/weren't.
Don't underestimate eye-hand coordination and an inherent "common sense" that some people just seem to possess over others. I've met people in my residency who could recite Miller to you, backwards and forwards, but either sucked at doing procedures or get such tunnel-vision when a problem arises that they can't immediately think of anything more than a single option to get them out of it. To me, these people are dangerous.
Anesthesiology is essentially critcal care medicine on speed. Not everyone who gets into the field is cut out for that. Trust me, I've seen this firsthand. And, as someone who (I believe) "gets" it, it can be very frustrating observing others who don't.
-copro