Yeah well I found ex university people tended to question almost everything they were told rather than accept the fact that their OJTI was experienced and knew what they were doing. I got so fed up of them saying 'at the college we were taught xxxxx' and me replying 'that was the college, this is the real world' that I gave up OJT. Plus many of them knew nothing about aviation let alone ATC before entering training and weren't really 'into' the task.