For example, why did modern civilization develop so quickly in Europe while North America didn't become "civilized" until outside influence became prominent.
Anatomically modern humans have been in Europe since about 35,000 BC, and in the Americas since about 16,000 BC, so Europe didn't actually get that far if you count the head-start.
Europe didn't become the civilization that Europe is without outside influence. Europe never invented agriculture. They did in the Middle East and that spread to Europe, through conquest or influence. A lot of Northern Europe still relied on hunting and gathering before the Roman Republic/Empire took control. Scandinavia picked up agriculture around 800ish, dropped it and then picked it up a few centuries after.
Europe never invented writing. The Middle East and possibly Egypt did and that spread to us.
Europe took lots of scientific understanding from the rest of Eurasia. Gunpowder's from Asia, our number 0's Indian and algebra's Middle-Eastern. Eurasia's the area best able to support a large, connected population with scientific advancements supporting each other.
Eurasia has the most useful set of plant and animal life. Chickens are Asian, wheat is Middle-Eastern, horses are native across Eurasia but were extinct in the Americas before Europeans bought them.