I understand not every decade was a clean break, but each decade has fairly distinct defining properties. It feels like most of the 21st century has been a single run on with smaller changes. I know sometimes the definitions don’t come into focus until later, but I’ve been around since the 80s and I can distinctly remember the changes between the 80s, 90s and 00s as they were happening.
I suspect because you haven’t had any major milestones this century. I graduated undergrad and 93 joined the army, met my wife and son. I got out of the army in 2000, A few years later, I adopted my son, A next major milestone was when he first went to first grade then when he went to middle school, then when he graduated high school school. I got a great job in 2000. I got an even better job in 2002. I got an even better job in 2006 and then I got a Phenomenal job in 2010. Lots of major milestones to break up the early parts of the century. Then I had similar major milestones between 2010 and 2020 and 2020 was the pandemic and blah blah blah blah blah