I am an instructor myself, and have plenty of students that I have taught to fly. And I have seen all types of beginning flyers. From those who pick it quickly to those you can't teach if you pound it in their heads with a hammer, and all in between. If the 2 people you are referring to say they taught themselves to fly both planes and heli's without crashing, I'd tell you to climb up on a table or get some tall boots, because it's getting deep (if you know what I mean). And if by some unbelievable stretch they did do it, well I want them picking my lottery numbers (because they are the luckiest two on the face of the earth).

Just my 2 cents worth