Regarding the perception of time, I have a complete opposite perception of the author. He mentions 20 as a middle point. I was after that, in my 20s when I first took real full control. I can remember the times before that. But I did so many "firsts" after that! My childhood years feel very short and boring to me; while the time after that feels gigantic and exciting.
There is so much in the world and so precious little time, I cannot really imagine running out of new "firsts" to do. Just I think many people never take control.
(The article itself seems to be more about raising children, being dad and fulfillment than the comments and title suggest)
Whilst I did more new things in my 20s, I do recall my perception of days as a child being much much longer. I have distinct recollection of feeling almost clinical depression when I was about 8 after being told that we would be going to the seaside tomorrow and not today. To a childs perception of time, it was an agonizing eternity.