[Delmania]

As I mentioned in my response, knowing that trees are used for various artifacts is important for the people who are implementing said artifacts. A well done implementation hides that detail, focusing on ensuring the implementation is correct. To use his analogy of Wehlings, there are standard procedures for blood transfusions, and the doctor doesn't need to know about the heart, he just needs to know who to ask since he doesn't work in a vacuum.

The other thing is that knowing a tree is symmetric and know how to reverse one don't count as new and unknown challenges that author mentions. Both are well documented and easily accessible to anyone who needs to know that information.

I recently had an interview where I was presented with a problem the company had to solve. That was new and exciting, not some minor detail from CS100 I learned years ago.