Sounds like you have a very bright young boy on your hands!!!
One of the things I would suggest is ensuring that you are balancing up the 'intellectual' stimulation with 'social/emotional' stimulation.
I work alot with very bright children who struggle socially. I'm not sure if this is your little boy, and I hope I'm not speaking out of turn, but I think it's really important when you have a bright child to make sure that you aren't 'watering and nurturing just one part of the garden'.
If possible, I would encourage you to find some way to organise informal play overs where he is just hanging out with other kids. Perhaps have a play over 1x fortnight.
Social/emotional development is incredibly important. There's a great book called "emotional intelligence" by Daniel Goleman which you may find interesting to read.
Anyway...again, I hope I haven't spoken (written) out of turn...and I wish you all the very best.
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