The difference I've heard mentioned is that current Chinese civilization has much more in common with the ancient Chinese living in the same area than Italy has with the Roman empire, or even than Greece has with Ancient Greek civilizations.

The examples I heard were that Ancient Chinese poetry is still understandable and taught to Chinese school-children, that Chinese cuisine in most areas has not changed dramatically, and that many Chinese religious traditions are practiced very similarly. Even the Mongol invasion of China has apparently had more of an effect of making the Mongols adopt Chinese customs than the other way around.

Please note that I may well have fallen for state propaganda on any or all of the above. I am not claiming to know any of these from direct scholarship.