One of the conclusions I’ve come to is that in connection to overall language ability or fluency, confidence plays a surprisingly large role in contrast to “absolute” ability. Certainly there are some things you just need to know and understand and be able to use, but sometimes – I’d even say often in my experience – the main difference between students who are “good at” English and others who are not turns out to be simply the level of confidence they speak it with.
It’s circular, to some extent as well: a confident student won’t be intimidated by trying out new language, making mistakes, or dealing with a text that’s a little above their level, and these are all important steps in the learning process. But the difference between someone who just speaks confidently with lots of mistakes and someone who constantly pauses, searches for the right word or structure and goes back to correct himself/herself is remarkable.
I’ve noticed “confidence issues” in teachers as well.
When I first started teaching, there were so many things I just didn’t know. I felt bad about it and sometimes even felt like I shouldn’t be teaching because of it. I took it upon myself to find out what I didn’t know – sometimes I would ask another teacher, but for topics that were generally available in reference material (grammar points, etc.), I felt like I should find out myself. I also just assumed other teachers knew this stuff. In fact, over the time I’ve been teaching I’ve heard teachers ask questions or in other ways show that they sometimes don’t know this stuff, even when they had more experience than me.
I’m not trying to imply they’re bad teachers for not knowing, and I’m also not trying to say teachers should present themselves as knowing more than they do. I suppose my point is more that “routinely or automatically deferring to others because they have a bit more experience and you assume they know more is not always the best choice”. The difference is not always that a more experienced teacher knows more; sometimes the difference really is that they present what they know and not what they don’t know.