Earlier quoted context omitted.
I am talking about responsibility as in being responsible for people (spouse, kids, grandkids in this case.) It's easier to "feel young" when you don't have that.
It's the "appropriate" that gives it the negative connotation. Maybe you meant "the responsibilities necessary to feel an age", but it came off as "the responsibilities you should have at an age".
I meant the former definition but they are intertwined for me so it makes sense that it came out ambiguously.
To elaborate:
As I grow up, I see in myself and others a deeper life satisfaction from being parents/grandparents at "the appropriate age." This was not obvious to me when I was 20-30.
So I don't mean for "appropriate" to suggest you owe it to anybody to reproduce, but I do believe that it's a path most likely to yield the most satisfaction for a typical person.
(As an analogy, I can say the "appropriate" weight for a 6 ft tall man like me is 170-180LBs. That doesn't mean that I am obligated to lose 20LBs, just that my life would be better if I did)