> Up to mid 20's, yes.

Are you by any chance over 25 but under 40? :)

I think it’s inarguable that experience is valuable, and age correlates very well with experience up to that mid-20s point, but around that point people start to settle into a groove and the extra n years experience is actually just the same year’s experience repeated n times.

The mid-20s transition is the most obvious, I think simply because teenagers so often incredibly hot headed. But I believe emotional development continues throughout life as people acquire more experience with age (at least until senility kicks in.)

I think so too, but it's much more gradual, and therefore, not uncommon that the age vs age maturity level heuristic fails for a given pair of people.