what about pre-school?

Be careful with formal learning if he is too young. You need to do things with your child that he enjoys. Why do we think we all need to do the same things at the same time as in a group setting?

Every person, even young children, need to go at their own pace and as your son develops, you will find he has wonderful gifts, which might not match everyone else on the planet and I say, "GOOD for Him!
Our society rewards adults that are "different" but in children, we think we have to make everyone the "same." Think of the salaries and fame of unique dancers, sports figures, etc who have a different skill set. Give your son lots of time to explore the world and let him grow up. How do you do this?

go places, walk outside, let him be part of your "work", help in the kitchen, use a mini-broom, do things that you are doing. talk about what you are doing, let him try what you are doing. play with a wash cloth while you are folding laundry, etc. Lot of good things at the local library for free.

And, when he is ready, a little group play such as Joy School, for ages 3,4, & 5!
This is a "do-it yourself" program with other moms using the curriculum
meeting twice a week in homes. After that, it was easy to go into homeschool though some of the Joy School moms went on to send their kids to K and first grade.
here are some links for more research.

http://www.joyschools.com/

Unique Preschool teaching children the fundamental "joys" of life.
Joy Schools are well-established (over 100,000 parents have been teaching) and truly unique preschools. The central belief of Joy School is simply that children, while in their most impressionable years, should be taught life's most important thing, various capacities for joy. A related belief is that children suffer not from being started in academic learning too late, but in starting too soon, before they have a basis of social and emotional self-esteem.

The Joy School preschool lesson plans are written for three, four and five year olds. An age variety in a Joy School group is no problem. In fact, it is often an asset as older ones teach and "tutor" younger ones. There are two different sets of lesson plans, so children can participate in Joy School for two years in a row.

When I did it we only had one year and it was the first set of Joys. Nice way to start out slow!
enjoy them while they are young!