I respectfully disagree.
As a reluctant member of the "older individuals" I too find myself giving a boatload less fucks than I used to, but the main reasons are (in no particular order):
1. I have got my crippling Generalized Anxiety Disorder under control
2. I have realized that I used to give way too many fucks about shit that didn't matter at all, and it was not worth it and actually detrimental
Mind you, those 2 are highly correlated and of interdependent causation.
What got me here:
Therapy didn't help.
Manson's book "The Subtle Art of Not Giving a Fuck" helped quite a bit, but was not "the thing".
Articles on "Don't be a victim...." "Don't play the victim...." and similar helped.
What helped immensely is to start blogging daily, and more often than daily, about the events in my life, my thinking, my reactions starting from the points of view that:
A) I am accountable for what happens to me
B) I am 100% wrong when something unpleasant happens to me
And that, in the course of a few month, changed my life in tangible manners.
While I am not a snowflake, I am a special case: I started low, very low; and - IMHO - I have come a long way in the Depression/Anxiety/Being_a_loser scale.
I do believe that to some degree something similar happens to most everyone who doesn't start for the same ultra-low point as me, with time we learn that when young we were wrong to give too many fucks about too many things.
But guess what? Giving way too many fucks about too many things is good for:
Business: Facebook, iPhone & Co
Politicians: from left to right
Religions: all of them (except for The Dude)
And that's why the messagings that we are bombarded with aim at reinforcing giving too many fucks about too many things (aka Anxiety) and the messagings aimed at kids/teenagers aim to create and instill Anxiety.
Mic drop.