I also agree. Whether theriosides turn out to be caused by the wishful thinking/confirmation bias, soul, alternate/dual socialization, or mental issue theory (or any mix thereof) age of a thinking/feeling state still depends on the maturity of the mind, and that is a hard thing to classify.
For example, when I was fifteen I was extremely political, researched issues of local, global and national politics diligently, and was always up for a good debate with anyone who would listen. People were surprised by my maturity, but was I really as mature as I often convinced people I was? NOOOOOO. <!-- s

--><img src="{SMILIES_PATH}/icon_razz.gif" alt=":P" title="Razz" /><!-- s

--> I know now that I was idealistic and blindly pushing for ideas that may or may not make things any better in the long run even if they succeeded.
Some people mature in different ways faster, so I always question it when people throw around the word too much, as if immaturity and maturity were actually black and white opposites.