One of my children can entertain himself for hours with a book; the other just needs art materials. Sometimes life can be perfectly peaceful. Sometimes it's complete madness!!
My four year old manages to turn every kind of toy/object into some sort of project...everything with a purpose that you might have to observe really closely to work out, or wait for him to explain. Nothing is really random and he gets so much joy out of what he creates.
Regardless of what others may think, this isn't the sort of thing can push - it is who he is and I love it about him :)