Greece was really kinda the birth of Western culture (lest just go with this thanks history textbooks). The Greeks developed the systems of government we know today, like democracy! Though Greek democracy differs from today’s democracy, it’s what started the idea. (Greek democracy was more direct and involved regular citizens in government while countries like the US have a representative type democracy.) Greece also was a center for the arts and architecture, just look at the things that came out of Athens! They’ve got the Parthenon for heaven sake! Greece also was a center for philosophy, Plato, Socrates, the whole gang! These philosophies can be seen still applied today. Math. You know that one guy Phythagaros? Yeah. He developed the stupid a^2+b^2=c^2. I hate geometry, thanks Egypt and Greece. The Greeks further developed medicine which started from the Egyptians really.... War! Look at Sparta, new technique and weapons! Fuuun! The Greeks traded like crazy! That was kinda a big thing. Since the Greeks were on the .... Greek islands .... they had few places suitable for farming. They resorted to a few crops that could grow on rocky terrain like olives, etc. They herded goats that could hand the terrain, etc. Fish. Everything else had to come from somewhere else. This trade spread Greek culture. Literature and Mythology. We learn all sorts of Greek mythology in school or whatever, from Zues to Eurydice. Also literature took a turn here and started to become... epic really. We have the illiad and the odyssey, the illiad being about the Trojan wars, and the odyssey about the trip back home from the war and posidon being rude. We also have theater! We get dramas and comedies! So yeah there’s a lot about Greece that’s kinda important culture wise.
The ancient Greeks are also highly revered for their sculpture work. Making use of their natural supply of marble, limestone and bronze, they created visions of their various god and heroes, as well as representations of important historical events and dominant elements of their culture.
The Treaty Of Versailles placed restrictions on how strong Germany could build its military and took away large portions of land that were taken during WW1. Loosing Lot of land right after obtaining it would make many citizens rather upset.