I have to say thank you for saying this. Even if you get some hate for it, it's absolutely true.

There is a biological reason for this behavior. The "calcification" you speak of. It is actually a real thing in neurobiology.

I know I write insanely long comments so I will keep it short.

When we are young our brains are in a "neonatenous" state. This childlike state of the brain is necessary so that we are "wide open" to the world and its sensations.

When we are children we gulp at the information the world offers us. When we are adults we sip.

Children (and all mammalian young) need this "turbocharged" brain and ability to make connections in order to learn how to survive. Biologically it's expensive.

You like cats. You know that there is a "window" to socialize them to people. Or else they become feral and never really tame. That's a physical change in their brain doing that.

Primate brains are similar. However, we have managed to streeeetch out our childlike neonate state so that it persists past our adolescence into adulthood.

Biologically, it's expensive. Our brains/bodies don't like it. Eventually, in almost all of us, the window closes.

We become adults. The calcification you observe begins.