How Do I Know What I Think Until I See What I Say?

Apparently, there's a term floating around for writers who don't plan ahead in their writing--pantsers. As in, these writers fly by the seat of their pants, I suppose, although it sort of sounds like these writers run around stealing other people's pants like frat boys during pledge week. As unflattering as the term is, the basic idea is that there are two types of writers: planners (who plan everything) and pantsers (who plan nothing), and many writers fall somewhere in between. Although I object to the term, I think the basic concept is sound. But this model fails to take into account the process. At the beginning of a new project, I am a pantser. I start with a character and an idea of what the book is going to be about* and once I feel like I know who the character is, I start writing. What's going to happen? No clue. What is the conflict? No idea. Just writing. As I said in another post, for me a good book is all about character, so that's all I need