When I was in USAF pilot training , there was an Afghan in training that had been washed back, from class to class, many times because he could not hack the program. To send him back to Afghanistan would create a State Department level mess. So, they kept him there, at Craig AFB, Selma, Alabama. He was still there when I graduated in October, 1963. His instructor let him solo once. It was such a disaster, he was “dual only” forever.
Flying is slightly more difficult that driving a Camel.