Where do all the good thoughts go?

Nature is inherently conservative: good things are retained and passed along, while bad things are discarded.  The maxim holds for nature, for nurture, for evolved and acquired traits.

This reflection led to "windshield thinking", driving through Portugal, about how nature might be conservative about experience.

Over our full years, each of us builds up a lifetime of experiences, carefully stored and indexed as memory, available for instant recall, association, and application.  It seems to me that this knowledge, built up over decades of survival, is too important to simply be discarded at death.  (How) Does nature, therefore, conserve valuable experience acquired by it's agents?

One idea might be preservation by patriarchy.  At a certain age, accumulated experience might simply be embodied as the wisdom of elders, passed along as oral teachings and oracle-style answers to questions.  I have to admit that there is an appeal to putting on robes, growing a beard, and becoming a patriarch some day. But this is a fragile and inefficient way of preserving experience. (In contrast, as women look forward to matriarchy, is there a contrasting role for passing judgement on right and wrong behavior and associations?)

Another might be preservation by externalization.  Experience could be written down as a memoir or treatise, placed on a shelf (or on the Internet) for future generations to discover when it became relevant.  However, I think that unless a work attracted a commentary it would likely be lost.  I'm reminded of the knowledge passed to the Eloi in Well's "The Time Machine": still intelligible, the knowledge carefully preserved has still ceased to have any meaning for them.  It's as sure a waste of experience as if it had died with it's creators.

The religiously inclined might argue that experience lives on through preservation of the soul or through reincarnation.  While I have no empiric data to suggest that this alternative is correct, it is at least romantically attractive to think that the imprint of my life somehow becomes part of a universal, collective, and eternal wisdom.  I imagine each of us sent out with free will, returning with the lessons of a unique conscious path, and, finally, on whole, creating the full fabric and texture of life's possibility.

Who can know the truth?  I surely don't, but driving through the mountains and across the plains, seeing the world, meeting people, sharing ideas, it just seems a waste that it doesn't end up somewhere other than my own mortal mind.