It results from knowing in great detail the knowledge of a single subject. It is as if the student went into the woods and focused on one tree to the exclusion of all other trees in the woods. The idiot savant is an example of the extreme case. Consequently, variety is stressed and considered important. We arrived at VMI shortly after graduation ceremonies.
Graduation is when the graduates throw their hats into the air.
The grounds keepers had picked up the hats and stored them at the welcome center. I was given one of those hats. My brother is 4 years younger than I and was not on the trip. He played with that hat and must have thought about its source. It had a lasting impression.