Opening the Drawer
This video presents the same text shown beside it, spoken and on screen. It adds nothing the text does not say.
Grading the stall tree on its locked rows produces the most important number in the unit: the gap between memory and learning.
Row seven — rain, weekend, festival, truly sold out. The tree asks its first question: festival — sold out. Correct. Row eight — rain, weekday, festival, truly not sold out. Festival — sold out. Wrong. The scoreboard: training accuracy six of six; test accuracy one of two. Read the gap honestly: the tree did not learn the stall — it learned six Saturdays, perfectly. The festival branch rests on two rows that both happened to sell out, an accident promoted into a confident rule, and the first festival weekday in the drawer broke it. That gap — memory outrunning learning — is the hazard every learner in this unit must manage, and the drawer is the only honest instrument that measures it.
A grade is spent once used for tuning — re-tuning until the same rows pass is memorization in a lab coat.