It made me empathize with all the teachers I'd had throughout my education - both the good ones, and the bad ones. Teaching is a tremendous responsibility. You're only put into your students path for a limited period of time - and you're responsible for transferring knowledge and skills they may use for the rest of their life. At the intro level, you may even play an important role in their career choice - you may help them discover a passion for design - or, you could be the reason they wind up dropping out of school or pursuing the exciting job opportunities at their local Pizza Hut.
Teaching made me extremely thankful for all the good teachers I'd ever had, the ones who realized that this was their calling. It also helped me understand why there were those that just seemed to be playing out the string. I may still not like them, but I understand how frustrating teaching can be.
In the end, even if you know your subject well and you try your hardest, and you spend extra time coaching them - it isn't up to you. It's up to the student to take the tests. It's up to the student to apply the principles & techniques you show them, and turn them into something new & unique. Something that's theirs, instead of yours.
Teaching was rewarding when a student turned in great work, showed that they had learned what they were doing, and asked about what they needed to take the next steps. I was lucky to have that happen with a few of my students. It's definitely not something I'll ever do again, but I'm glad I gave it everything I had.