First I was a baby in momma's tummy.
Then I was a little boy.
Now I am a big boy.
Then I'll be a grown up...
...and then I'll be a duck!
I don't think that way. Most people, even the most creative people I know, don't think that way. We have certain constants, such as: human children don't grow up to be ducks.
But what if they did?
I will admit to coming to him when I've written myself into a corner, explaining the story so far - with no simplification - and then asking his opinion on where it should go. Sometimes he just asks questions about a few things that stuck in his mind. Other times he'll continue telling the story, usually with an expanded cast, and swords. And ducks. Sometimes he'll do that thing that all parents know and dread.
Tabitha rode her motorcycle to the end of the road, looking for Hester. She wasn't there so Tabitha burned the shack to the ground.
Because she was so angry at her sister, and her sister loved that house and had put years into rebuilding and filling it with things she loved.
Because when they were growing up, they were moved from one distant relative's house to another, living jointly out of a suitcase full of clothes they were quickly outgrowing. So she wanted to have a place full of her things, and walls that were always the same.
Well, their mother passed away when they were born and their father was sent off-planet, after which the force fields locked so that spacecraft couldn't come back.
Well, it was actually a conspiracy. A heroic general and the most powerful politicians in a party went off-planet to great fanfare to christen a new colony. They were supposed to be gone a month. But while they were gone, two ambitious businessmen and a young chemist who desperately wanted to prove himself, arranged for a coup following the release of a chemical that would obscure the sky.
You see where this can go? How broad or how deep you'll be forced to drill down if you just keep asking why? How you will start thinking about aspects of your characters or plot that you never would have explored on your own? I just hope I remember these lessons when I achieve duckhood.