You were never taught which chord should come next — you absorbed it. The framework goes back to Leonard Meyer (1956), who argued musical emotion arises exactly when an expected continuation is delayed or denied; meaning lives in the gap between prediction and arrival. And the predictions themselves are learned statistically: hear thousands of songs and your brain quietly tallies which chord tends to follow which — the same machinery that learned which word tends to follow another in your language (Bharucha & Krumhansl mapped these tonal expectations in the 1980s; corpus models have sharpened the picture since). That's why 5 → 1 feels inevitable to a Western-raised listener and merely arbitrary to someone who isn't — the 'rules' of theory are a description of statistics you already internalized, not a law. Two consequences fall out. First, the mere-exposure effect (Zajonc, 1968): repetition alone breeds liking — up to a point; Berlyne's inverted-U says overplay eventually dulls it, as every radio listener knows — which is why a vamp earns a hook and why a jarring reharmonization sounds inevitable by the third listen. Repetition builds the expectation a surprise will later bend. Second, and finally: you can only break a rule the listener can feel is straight. Rock kept the parallel fifths classical banned; jazz made unresolved dissonance a resting place; metal built cathedrals on the tritone the old counterpoint books policed. Learn the defaults not because they're sacred, but because breaking an expectation the listener holds is precisely how surprise — and therefore pleasure — is made.