I became convinced of the vital importance of early childhood when I was a 21 year old medical student. An instructor in my neuroanatomy class lent me a set of microscope slides that after 60 years still blow me away.
I’ve reproduced two of them here. They are from exactly the same part of the brain, but taken at two different ages: birth and two years of age.
These are NOT diagrams or schematics. They are magnified photos of actual brain tissues. The tissue preparation shows the fibers that serve to connect nerve cells to one another and thereby transmit information.