But I don't know it off the top of my head, because I never did a CS degree, and frankly it's knowledge that's not very useful to memorise because it is very ea

But I don't know it off the top of my head, because I never did a CS degree, and frankly it's knowledge that's not very useful to memorise because it is very easy to google. If the confluence of 2 or 3 requests you were implementing were to cause a nasty O(n^2) or O(n^3) time or space workload, would you have a good chance of realizing it? If your answer is yes, then you'd have what I'd be looking for. If your answer is that you'd figure it out after the fact, after the problem reports came, by Googling, then you would cause a problem and require an additional spate of diagnosing and patching that a better trained programmer would not have.