The nuke track is: After A school (Electrician, Electronic, or Mechanical) you go to Naval Nuclear Power School. From there you go to land-based prototype training on an actual reactor. From there you go to a boat to try to qualify.
So. You know those whiteboard interviews that software engineers love to gripe about? In software engineering, you only have to take those once before you're hired, and then you can start forgetting them.
In the Navy, you take those continuously, and they are somewhat more extensive. You have them at the end of your practical training phase on land, you have them at every individual job you qualify for on the ship, Naval Reactors comes and gives them to the entire crew every year, and so on. In my six year tour, I must have gone through at least 150 oral interviews of one kind or another.
On top of the constant interviewing, there's also continuous written exams, and various engineering casualty drills (eg, model that something breaks, and observe the crew respond to the failure).
If you're lucky enough to get stationed on a 17-year old boat, then you get to constantly exercise the fundamentals, too. As various pieces of equipment fail in new and novel ways, the troubleshooting process drives you to constantly construct, support, and/or refute hypothesis as to why it broke and just what must be done to fix it.
If you forget it, it'll come back to haunt you. Nukes are constantly being tested and requalifying. The NAVY does an outstanding job of punishing a nuke that does horribly at either of those.
