My son has a wonderful memory, he is now 4 yrs old and can read at a 1st grade level, he does basic math, name many shapes that even adult have difficultly with. He sings many songs, America the beautiful, Star Bangle Banner, Sea of Love, and many children songs. A teacher that we often see says that I am "ruining" him by teaching these things because he will not be social enough for his grade when he does eventually get to Kindergarten if he grade skips. Any insight would help because in Alaska there are no Gifted and Talented programs for kids under the age of 7. He doesn't show any stress from learning these things, and loves to have new information.
The idea that you're 'ruining' your son is a very harsh one and I wouldn't agree. Your son is happy learning with you - that's a sign that it's the right thing to do, not the wrong thing. Other 4 year olds would be in preschool and learning the same things that you are teaching your son - good for you.
Will he know more than other children when he begins kindergarten? He likely will and maybe that's what worrying your teacher friend. Maybe he will be a bit bored in kindergarten but there's so much more to kindergarten than basic math and songs and reading actually. Being in any grade is to be part of a group of children and often that's so much fun and exciting that children can be content with the academic curriculum even if they already know much of it.
Teaching a child at home does not make 'unsocial'. If your son enjoys it, it's clearly the right thing to be doing. There are so many books for his age -he could read every day, you could read aloud to him every day and there would still be books to read. There's no limit to learning and the more we learn the more 'social' we usually are.
my son is now entering his second year in Headstart, he knows now that his reading is above other students but says he will help the teachers to read to the other kids. Math is a love/hate relationship with me and him. I hate it and he loves it. I tell him to use the abacus now to find answers :) we talk a lot about how we should teach him, he decides now and he is happy with me looking for answers :)