My DD was driven to learn academics from age 2 to 3.5. She is almost 4 now and although she still reads and loves math, academics is no longer her priority. Her interest has shifted and those days when she was reading 10+ books a day and only wanted to watch science DVDs are long gone. A year ago, if anyone told me that she'd only want to read books at bedtime and would choose watching My Little Pony over anything else, I would not have believed it. She's still the same child with a very curious mind and has passion for learning but her passion has been redirected to music and art.
If I can offer an unsolicited advice, it'd be that your DS has a lot of unstructured free playtime with open-ended toys to stretch his creativity and imagination.
