I'm sorry but saying it's 1% knowledge of your subject is nonsense unless you are teaching entry-level subjects way below your level of knowledge (such as key-skills). Being knowledgeable in your field is absolutely essential
imo. I see evidence of this on a daily basis where I am a better teacher than my colleagues at certain things precisely because I know about the subjects then they do. I also feel less equipped to deal with certain things because I am merely teaching from texts and other resources rather than from my own knowledge/experience.
Furthermore, although actual experiences has taught me way more than the PGCE it has equipped me with methods and knowledge that experience would not have. It's still boring as hell though.
I teach computing and multimedia to both teenagers and adults in an FE college, btw.