I teach medical students...about 8-10 hours of didactics per year. It's incredibly time consuming to update lectures, integrate audience response questions, review notes, and make sure I've improved the materials. I ask myself why I do it? Seriously. Sometimes, a quarter to half of the students don't show up to class to start with (because attendance is not required and everything is recorded for them). Sometimes, there will be a student that complains that there is too much material or not enough or it's not relevant for the boards, etc. Don't get me wrong...I really appreciate feedback but some feedback can be a little weird. On top of that, teaching doesn't give people as much "academic currency" as an original scientific paper or a grant would. I see teaching like bonds...it's safe in the long term but the yield is low. This is in contrast to research which is more like small cap index funds...high risk and high rewards.
But, my attending inspired me today. I am on neuroradiology rotation and was reviewing/ "reading out" my cases with my attending. He made teaching points with each case. He reviewed the sphenopalatine fossa with me today and reviewed the CT anatomy and its communicating channels to the nasopharyxn, superior orbital fissure, vidian canal and into the intracranial fossa. My neurons which had been in hibernation started to synapse and fired a giant light bulb in my head. We reviewed a few other skull base anatomy like the Versai canal, which I didn't know existed, which drained the infratemporal fossa, etc. I was totally inspired and so grateful for finally (sort of) understanding skull base anatomy. At that brief moment, I thought to myself, "I might totally love doing neuroradiology." For two minutes of my life, I wanted to be a neuroradiologist. I realized how much teachers can inspire students. If the instructor is great and the student is ready to learn, great things happen.
Unlike research which is more like "self-inspiration" and developing your personal talents and skills to build something, teaching has the unique quality of inspiring others and passing it forward. Maybe this is why I'm told that finding the right mentorship is so critical? Maybe this explains why Nobel laureates (in medicine) are friends even before they became famous. Inspiration is an incredibly potent vector to spread your vision and to create something more.
If you like teaching (and I do), the pain and incredible amount of time needed to prepare the materials, etc may be a minor setback to the impact the instructor can have on the individuals.
I think in an academic environment, teaching is not always given the credit or weight it deserves compared to clinical revenue or even research productivity. Certainly, we can do so much better to attract and maintain outstanding people in education and develop metrics to encourage and foster stellar education. Until then, I'm grateful to all the instructors around me who've spent the time to beef up my neurons and keep my brain from atrophy with not much monetary return for their time or energy. But, they've done something more potent...they've passed along their desires / habits/ knowledge to me so I can be more effective at what I do.