If humans have been around for 200,000 years, why did we only create large civilizations in the last 5,000 years or so?

We are currently living in an ice age: the quaternary glaciation, which started about 2.5 million years ago. This ice age has seen brief warm periods at regular intervals. On a chart of temperature over the last 2.5 million years, the warm periods look like heartbeats on a cardiogram.

Most of the warm periods have been quite short, with two exceptions: the most recent being the current period, which has been warm for about 12,000 years — and will probably continue to be warm for another 50,000 years. The last warm period before the current one was the Eemian Age, 130,000 years ago. At the time, humans were still mostly restricted to Africa and Asia, but we can't really know much about their activity — the intervening 100,000 years of glaciation and sea-level changes would have wiped away most traces of human activity.