The Zen initiate Pat was studying a book of koans, and folding the corners of pages that he found particularly meaningful.
Pat’s Master noticed this behaviour, and she approached Pat and twisted his ear. Pat yelped and his Master returned to her room.
During their next study meeting, Pat asked what the purpose of this was. His Master said: “My most dim-witted students must be marked.”
With this, Pat had great satori.
Pat's Hyperbolic Arboretum 