I experienced a similar frustration when I was regularly interviewing bods for fairly low level jobs several years ago. I couldn't understand why someone who claimed to have umpteen years experience in equity settlement couldn't describe the trade cycle or work out simple percentages. I ended up sitting written tests for all candidates, which went some ways to filtering out the crud.However, I have since had a few sobering moments myself, in more recent years, when the boot was on the other foot. One was when the interviewer was looking for such a specific answer to a (easy) question. Knowing much more about the subject matter in question than the interviewer, I found it a rather bewildering since I wasn't coming up with her (rather dumb) answer and no doubt looked bad in her eyes. My second experience was a first round telephone interview for a role I had no background on when I had technical question fired at me, without prep or warning. The subject matter, even though on my CV was on something that I wouldn't have touched for two years minimum and was pure academic, not professional (and this should have been clear). I would have performed fine with some preparation but no doubt looked very slow compared with someone who graduated last week.If anything, as a candidate having two "bad" experiences of technical interviews is not bad going. Then again, my CV is severely understated and I don't think anyone who knows me would accuse me of "inflation" of knowledge or experience. I do, however, think that it is hard for an interviewer who is doing the same thing everyday and who has been in the same job/company for many years to gain an easy appreciation of a candidates ability to pick up a job if they have been out of that field for a while, or only have peripheral experience of it. It is frustrating, thought, that i will grant you.