If you only learn what’s on the test, you’ll only be ready for tests.

A syllabus is a sample of a subject, chosen because it can be marked in an hour rather than because it is the useful part. Studying only the sample prepares you for the sample, and the moment questions come from the world instead of a paper, the gap shows. Exams are a measurement that gets mistaken for the target.

Learn one thing a week in a subject that will not be assessed. The chapter nobody set, the bit a teacher mentioned in passing. It costs very little and it is where understanding tends to come from.