My favorite story was from one of the early homeschooling pioneers --- was it Ray Moore? -- who told of a little baby girl born missing most of her brain. Docs said she wouldn't live, so the parents might as well leave her in the hospital and say goodbye, but the parents, homeschoolers, decided to take her home.
Their older children had small, regular care-giving tasks to do with the baby, feeding, stimulation, giving her baths, just carrying her around a lot. She survived but for several years never seemed to respond. Her facial expression never showed comprehension or attention or interest, and her muscle tone was terrible: at about 3 or 4 all they could do was to prop her up in a sitting position. But they always talked to her, sang for her, read to her.
One day at the usual reading time, she was propped sitting on the floor, with her back to the couch, but the sister who was supposed to be reading to her was delayed half an hour. When the sister came back, she found the "unresponsive" brain-damaged little girl had crawled over to the bookcase, pulled the correct book off the shelf, and actually had managed to open it to the correct page.
Later medical investigation revealed that she never spoke or even appeared to comprehend anything because she had almost no control over the muscles of her face.
The family started on a program of exercising her face muscles and general strength-building routines---
I don't know, last thing I heard (this was years ago) she was reading, writing, laughing, and ice-skating.
Expectations have fallen ever lower in that area to avoid disappointment and frustration.
Thanks for the ping. What a wonderful story.