Writer's Aid discussion

I've been following a workshop to encourage plotting - outlining - based on the Hero's Journey (Campbell) and the Writer's Journey (Vogler).

For the first time ever - I have outlined a complete novel, using these principles. And it was easier than I thought it would be.
I'm now encouraged to write this story, but need to finish other projects off first.
Still, at least the story is outlined. Never thought I'd ever say that - or write it!

Questions - What happens when your story/characters take off on their own? Will you push them back in or let them wander?