The closest I came to precocity was when I was four I used to annoy my mother by scratching on paper with a pencil and asking her what it said. She made an attempt to get me in school at the age of five so I could figure out for myself that my scribblings never said anything, but the school district nixed that idea.
The only thing she could do was try to teach me how to read herself. That pretty well worked. When I entered the first grade I was able to read anything they threw at us.
I guess I had a fair start at arithmetic, too. How I learned this, I don't recall--maybe my father taught me--but I do remember that a couple older neighbor boys where I lived when I was three threatened to wash my mouth out with soap for lying. I had told them I could count to a hundred, I think; but probably I could have made it to 999, at least, given some time. I don't recall whether I demonstrated to those kids; I don't remember eating any soap.