Making lists and diagrams out of long reads is not a 21st century student invention. It is one of the most common forms of marginalia found in medieval manuscripts.
Image: Deventer, Athenaeumbibliotheek, 101 F 23 KL (12th c): diagram, 13th century
We have all seized the white perimeter as our own
—Marginalia by Billy Collins
The jottings we make in the books we own may well be among the highest tributes we pay to authors.