You know, I think it is really appropriate to just take charge of the conversation and talk about his burping, his tiny hiney, his stomping in mud puddles, his matchbox car worship and whatever else that might be quite typical of him as a 3 year old. So many people forget that Children who are gifted are also first and foremost children just as they are children with blonde hair, children with tiny behinds, children with motor mouth, etc.
Try to stop stressing because that will only get translated into frustration for your son.