The hardest thing was learning to write. I was 13, and the only writing I had done was for Social Studies. It consisted of copying passages right out of the encyclopedia.
Peter was 2 years and 10 months old when we began to study him. He was afraid of a white rat, and this fear extended to a rabbit, a fur coat, a feather, cotton wool, etc., but not to wooden blocks and similar toys.
If quantitatively the American achievement is impressive, qualitatively it is somewhat less satisfying.