Failing an interview may not have to do with not knowing about the trade. Yes, there are trade/training questions that are quite specific, but there are other questions too, which have nothing to do with studying. Reviewing information up to the last second is only going to make some one nervous, if you are forgetting something at that point it's either not important or you didn't start preparing in enough time. For the OP, if you haven't had many interviews before, a quick google search can give some interview taking strategies that may help you feel more prepared and ready to answer questions. Confidence is huge, so get a friend or family member to practice interviewing you. Best of luck next time