Not really. There's just as many opportunities in every age, it's just that you've been burned enough times to realize that the majority of opportunities are nothing of the sort.
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 for not having a very formalized process for adults who want to change buckets later in life.
The other problem is for lengthy training periods. Giving up 10 years for education and training when you're 20 is acceptable. When you're in your 30s or 40s, why that's a substantial amount of the time you have left before society decides you are old and must retire.
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 ;)