I'm concerned that this "every knows" is increasingly becoming a true social problem, unsolved by current technology - in fact, worsened by it.
Knowledge about a field transfers best by hands-on association with people who practice it. Before widespread IT, communities of practice were local and relatively homogeneous; so it was easy to share the essentials of a field quickly, and get newcomers up and running with best practices.
Nowadays however, communities of practice are widespread, coming around all the world with very different backgrounds, communicating through low-bandwidth channels, and we're flooded with information so it's difficult to ascertain what is essential and what's accessory.
It is much more difficult for an outsider to grasp the essential qualities of a field they want to enter, as there are usually no guides comprehensive enough to detail everything you need to know.