The single most important thing that a martial arts practitioner can do- regardless of rank or ability- is learn. It is the founding principle behind every exercise, every practice, every test, every tournament- everything. So of course the people that we learn from are vitally important to this process.
The open hand represents the scholar while the fist represents the warrior. Knowledge above force.
The process starts at the bottom- students teach each other by working together, practicing specific techniques with each other and learning from each others mistakes and the corrections received from instructors. Though there's no formal teaching going on just yet there is still a lot of informal exchanges which lay the groundwork for teaching later- helping a classmate with a particular technique or practicing a difficult move together.
Once you reach black belt there is a requirement that you instruct on some level. The younger dans help senior instructors by demonstrating for the gups (colored belts). The older or more advanced dans may be given one or two students who are falling behind to break down forms or drill so they can get reps and catch up. The adult dans (myself included) act as senior instructors and run classes for the gups- teaching them new forms and one-steps, tweaking techniques, preparing them for testing. No dan trains themselves during the first class- we're all instructing or helping instructors. Why do we sacrifice our own training time to help the gups? Because someone did that for us, and that's how we became dans.
We have an instructor's clinic every year where get specific tips on how to teach- everything from breaking down forms one step at a time so that the kids can learn them piecemeal to techniques used to energize and motivate the kids to tricks to help us deal with difficult students. Our Sah Bom Nim is an elementary phys ed teacher himself and has extensive education on learning theory, classroom structure and lesson panning and he freely passes this information down to us so that we can get better at what we do.
Above the senior instructors are the masters and right-hand men of Sah Bom Nim. They run the class when Sah Bom Nim is away, teach the younger students independently and help out in any way they are needed. And then, Sah Bom Nim is the head of our school and subsequently the head instructor for all our techniques. And yet, he as a teacher is only as good as the learning that he himself continues to do.
Thankfully, our Sah Bom Nim has a voracious appetite for knowledge. He not only continues his training by finding masters in other styles to train him (and us by proxy) but he is constantly reading, watching videos and re-tooling techniques through what he learns. He absolutely blows my mind with how much he knows, how much he is constantly learning, and how much he has grown in his instruction. It's arguable that a school is only as good as its Sah Bom Nim and I'm happy to say that ours is incredible. Because of him, I have no doubt that I will absolutely never stop learning.