The Life Cycle of Chinese Dragons
Dragons are often described as being "ancient" and that's certainly a feature of those from China.
The Serpent's Egg
The life cycle of a Chinese dragon was long and arduous, taking many thousands
of years.
When a dragon was first born, it was imprisoned in a small stone known as a serpent's egg. In this form the dragon had to spend a thousand years under the sea, followed by a thousand years in the mountains and finally a thousand years amongst mortal men. Only then could it escape its prison and grow into a real dragon.
Most Chinese dragons were wingless, though some reports say that after a further thousand years some dragons could grow wings.
All of which means that any Chinese dragon met by a human must be at least 3000 years old. If it has wings then it must be aged at least 4000 years.