Don't mistake institutional and cultural memory, which are not the same thing! A memory in the intellectual elite sense, and a political cultural memory, and a widespread low-cultural set of norms and understandings are also different things. All apart from the institutions of state, or religion, or bureaucracy, or commerce, and so on, which may have traditions and functional memory going back decades or millennia, depending.

That being the case, modern China has an institutional memory going back decades, maybe a century at most. It's nowhere near 4k years.