system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Humanity has existed for at least 100 000 years. Why did all major civilizations around the world develop only during the past few thousand years? There's like 90 000 years of nothing.
gpt
Well there was an ice age in there that slowed things down.  The advent of agricultural was important too.  That allowed people to organize around a particular area and feed enough that people can start having specialized jobs.