Across more than a century of educational innovation, a recurring promise has emerged: master the system, and the mind will grow stronger everywhere. The latest iteration of this promise arrives in the form of AI tutoring platforms, which show impressive gains on assessments closely resembling their own training environments — yet those gains tend to dissolve when students face broader, more unfamiliar tests. This pattern mirrors the collapse of the brain-training industry, and it points to the same underlying misunderstanding: that learning confined to a narrow context rarely travels far beyo