At the very start of my career, I got to work for a large-scale (technically/logistically, not in staff) internet company doing all the systems stuff. The number of lessons I learned in such a short time was crazy. Since leaving them, I learned that most people can go almost their whole careers without running into all those issues, and so don't learn those lessons.

That's one of the reasons why I think we should have a professional license. By requiring an apprenticeship under a master engineer, somebody can pick up incredibly valuable knowledge and skills (that you only learn by experience) in a very short time frame, and then be released out into the world to be much more effective throughout their career. And as someone who also interviews candidates, some proof of their experience and a reference from their mentor would be invaluable.