History & CultureMental model
Nobody ever woke up in the Middle Ages.
Periods are retrospective filing aids, not natural boundaries. In the 14th century Petrarch coined the idea of a dark intervening age in order to read his own time as a rebirth. The Italian and English Renaissances sit about 200 years apart, and "Dark Ages" is now considered too loaded for scholarly use.
Useful: For any period boundary, ask who drew it and what purpose it serves.
Source: en.wikipedia.org