It's not about being "obvious." It's about understanding the most basic concepts involved with using a piece of equipment that is central to their job and has been that way for decades.

I wouldn't want ride in a car with somebody that couldn't remember what the difference between red, yellow, and green traffic lights are, or couldn't remember how to activate their turn signals or windshield wipers. And I certainly wouldn't want them operating a vehicle as a core part of their everyday job.

Now I'll grant that in general, a car is far more dangerous than a computer. But the principle still holds, these are not tough concepts to understand, takes literally 5 minutes to explain at most. Plus, they haven't changed in at least 30 years, so it's not some new fangled techno-babble.