MagicPenguin
One Thousand Club
You do need some planning to write a book tho, unlike rping where I read as much as I write. G.R.R Martin himself hasn't and probably will never finish ASoIaf, one of the reasons I can't get into the series despite it looks soooo appealing.
Oh, he'll finish it. He fucking better, I've been waiting for book six for like five years now.
A lot of famous novel writers are gardeners. Stephen King is a really famous one. He just comes up with a bunch of characters, puts them in crazy situations, and basically says, "okay, what are they gonna do now?" And that's how he writes his books. Seems to be going pretty well for him.
I myself tend to fall more on the architect side of things. Even in RPs, I like planning things out to some degree. When I try to write without having some idea where I'm going or what I'm doing, I feel like nothing of value is getting done. I also just really like getting down into the weeds and figuring out little details and making connections between different plot elements, which I think the architect approach is good for in a lot of ways.
J.R.R. Tolkien was a famous author who liked to plan things. He spent like 20 years putting together his world before he finally wrote anything. I've heard J.K. Rowling is another one who likes to plan ahead, though I don't know if that's true.
Another of my favorite authors, Brandon Sanderson, likes to plan things out. He talks about the pros and cons of each approach here, which I think is just really interesting: