My DS is 6 but will be 7 in a few weeks. He is going into 1st grade (September birthday missed cutoff)
He devours chapter books, that is when someone else reads them to him ...
That's awesome though - your DS has a content-devouring brain
My DS8(ADHD), meanwhile, often loses track of what's happening if someone reads to him (his mind wanders, although this can depend on the book). He's either engaged and constantly interrupting and asking questions, or he's quiet and then will suddenly say "wait a minute - what is this about again?" The only way he can keep track of what the text is about is if he reads it himself, out loud.
He's incredibly imaginative - sometimes he'll tell us he doesn't want to talk because "I'm imagining! Please be quiet!" ...but it interferes with his focus unless the story being read is more interesting than what's going on inside his brain. (This sheds a huge light on his attention difficulties at school

)