The plasticity of our brains

I am getting older. And I have recently gotten aware of a new state of mind. I literary feel how the plasticity of my brain is disappearing. It is a very interesting feeling.
As an undergraduate, when I was taking a class in vector calculus for example, learning about the curl operator in 3-space you were given the definition and you were building a conceptual feeling for what that operator was doing with a vector field. You could actually feel the spatial properties being molded to you head.
This does not happen nearly to the same extent any more. And I think this has to do with me getting old. But it is interesting to speculate in how this plasticity manifests it self. Is playfulness a consequence of this plasticity? And if humans manage to significantly extend our lives, lets say to 500 years or so, I think it will be crucial that we also manage to control brain plasticity. If you only develop significantly during the first 50 years or less, a 500 years life will probably be quite painful.

A solution to the Fermi paradox and the missing 96%

96 % of the universe mass is missing. At the same time we have the problem of the Fermi paradox. Combine them, and what do you get? Lots of type II and II civilizations.