Knowing how a camera works is maybe 10% of it. The other 90 is not being afraid to put that camera into a given situation and start shooting, no matter what you think or feel about the subject matter. Sometimes you can control your environment, while other times the world doesn't care what you need to take a great image. 
Dead's not going to say any good shot is a lucky shot. But we will say that a number of Dead's best had a 1 in 1000 chance of turning out, and for many of them we had no idea as to what we had until digging through thousands of images after the fact.
Dead's traveled the world a few times, and the camera goes everywhere. Not that it has to be a special trip to make good images, as many of our best come from right here at home and when we aren't even looking for that great shot.
Sure, we stage our share of shots, but many come from just being at the right place at the right time, and throwing ourselves into the thick of it. Shooting.