To be honest my first child was speaking in a complete sentence when he was 12 months old, people don't believe me either, but he did. He knew all of his letters by 14 months as well.
Complete sentence at 12 months is AMAZING! Very cool. You must've gained some very interesting and unique insights into the workings of an infant mind.
You haven't worked with him at all?
Not intentionally. We've read to him a lot since birth - but the goal wasn't early learning per se... it was more just a fun activity to do together. But, like I said, I think he learned his letters through that leapfrog phonics refrigerator magnet we have. (Yes, I've been one upped in parenting by a kitchen appliance. LOL!)
Does anyone in your family have a photographic memory? or have a high IQ?
Both my husband and myself were "gifted" students. I had a highy gifted IQ when tested in elementary and junior high... not that you'd ever know it now. I'm pregnant with our second now, and since my son doesn't sleep much I don't get to sleep much. That combination of factors have contributed to me feeling very very dumb with pregnancy brain as of late. (Got into the shower with socks on the other day.) But back to the question at hand... aside from myself and my husband, my brother was always a 99th percentile kids too.
And being a homeschool mom/teacher you may want to think about later on homeschooling, that is if your public school system does not have the capability to advance your child when needed. Some of the public schools here do not have the resources to advance a child when needed based on their level, they just let them hang out instead of nuturing their gift allowing the child to reach his/her full potention, something to think about in the future.
I honestly don't feel confident in my ability to homeschool right now. That could change, of course. I don't know much about the local school system - but we would absolutely be willing to move to a better school system if necessary. We're lucky that my husband works at home and could do his job just about anywhere.
Thanks for your suggestions and links to resources!!