Sure, some aspects of the 00s were shit, but that felt like a bump in the road: things were still on the up-and-up overall, and the general expectation was that we could change the future for the better, resolve the world’s issues, and live better lives than our parents. That all came crashing down sometime around 2010 with the Great Recession, failure of Occupy, and realization that Obama wasn’t the knight in shining armor we’d literally hoped for. So the difference is that Millennials remember a pre-9/11 world and the less-great-but-still-hopeful early 00s, whereas Gen Z doesn’t.