Marc relates a strange experience when training people in a large company. Although they pretented to know Java, they actually did not know much about it.
We have a saying in France : "in the land of blind people, one-eyed ones are kings". Marc obviously met the one-eyed people of that company. But one-eyed kings can only keep their crown if the land's frontiers are kept closed, because the outside world is full of two-eyed people...
Now I sometimes think the opensource-java land is populated by strange aliens that have three eyes. The third eye is the community that we are living in : nice projects and smart people decuple the knowledge... and widens the gap with one-eyed kings.
Beware, ignorant kings, Cluetrain is at work, and frontiers will fall down rather sooner than later !