Earlier quoted context omitted.
I think the better example is that when you're young, the world hasn't sorted you into a bucket yet. Education, university, and your first jobs are largely that process: figuring out in which bucket you'll fit in society. When you're older, if you want to change buckets, there is no easy mechanism. Even going back to university is clunky. It's by no means impossible, but I do wonder if we're missing out as a society…
As the exception to that rule, I changed careers completely in my 60s, and picked up yet another at 66. You are welcome to remain in a bucket, I'm way too busy.
30-50 is hard, primarily due to obligations you can't just walk away from. Your mortgage drains $Xk/month and the kids need braces is a bad time to try and find yourself ;)