I agree that Greece was a great civilization. However, its achievements were over  inflated in the 19th century, so that the Europeans didn't look inferior to the Asian and African countries that they had conquered. So they made the Greeks and Romans into their spiritual ancestors, thus establishing a continuous line of civilization. Even though most western European countries were really civilized for less than a thousand years.

As an example - you have probably heard of the Magna Carta. Have you heard of Hammurabi's Code, which stated the limits of a monarch's powers 3000 years before the Magna Carta? You have probably heard of Machiavelli. Have you heard about Chanakya and his book the Arthashastra, which talked about moral and immoral means to stay in power, about 2000 years before Machiavelli?

Eastern achievements were understated to justify colonialism in the 18th and 19th centuries.