I think you're right that it's an example of hyperbole. The important thing to understand in the context of this discussion though, is that hyperbole is not ung

I think you're right that it's an example of hyperbole. The important thing to understand in the context of this discussion though, is that hyperbole is not ungrammatical. It serves a function in a sentence to communicate emphasis or draw attention. Saying 'it is quite literally the cradle of Chinese civilization' is no less grammatical than saying 'I have a tonne of work to do' or 'downtown is dead on Monday nights'.