A friend of mine once told me about an unusual experience that he encountered in Army basic training. He said that on the last day, as the drill sergeant was calling out various names, people realized there was one guy in the platoon who had gotten through the entire training cycle without being noticed.
He said people looked at one another and asked, "Who is that guy?"
This was regarded as both remarkable and admirable. It was remarkable in that, just like in the movies, you get to know everyone in a platoon, maybe not real well but well enough to identify the slackers, the intellectuals, the streetfighters, the jocks, and the nerds. You know the Bill Murrays and the John Waynes and everyone in-between.
Except, apparently, this one guy.
My friend said the guy was suddenly regarded as a hero - the Invisible Man - because he'd managed to slip into the background and avoid the hassles and the chores. No one ever recalled the guy being picked on by the drill sergeant or drawing guard duty. They didn't remember him from long marches or the rifle range. He sort of cruised through.
There are some jobs in which the ability to assume a low profile is a highly desirable talent. A prominent figure in French politics was asked what he did during the French Revolution and he replied, "I survived."
The Invisibles, if I may use a convenient term, know the work schedules of unpleasant people so they can better avoid their paths. They quickly determine when a meeting should be ducked. Their personal radar is impeccable. They find hiding places; nooks where no one goes. They don't draw unnecessary attention to themselves. They go on trips just before all hell breaks loose.
Watching a true Invisible in action is akin to watching Houdini. Of course, you never really see them; you just sense traces of their presence. When that's all you get, you know there is an artist at work.