[drakonka]

I can't comprehensively answer this question as it is very broad, but one type of knowledge that sprang to mind immediately when I read the question is knowing what you don't know.

I think after we work with something for a long time it is easy to assume we know almost everything about that thing, or at least everything that matters, even though much of the time we are only exposed to a small subsection of it. We may be very effective and knowledgeable in an area in the context of our day to day work and lose sight of how much more there may be to learn about it. This is a shame because we may be missing out on more exciting and useful knowledge in an area we care about. Remembering that there is always more to learn and recognising that we may not know as much as we think we do about something is in my opinion important and can help guide further learning decisions.