I suspect your friend is quite correct in saying that a number of people joining the college didn't know very much about ATC. That's kind of the point of the college !
Phew! Thank God for that. For a minute then I was freaking out and thinking I had slipped through the selection process net without really knowing anything about ATC at all. I mean I "know" things about ATC, but I know bugger all compared to a trained ATCO....
I had visions of me turning up to CATC in July and being asked to do some super-duper thing on the first day. My mind has been put at rest now thanks. Thank God the word "college" at NATS still means a place of learning, like it does in the rest of life!