Totally agree with what Chris says. When I first started writing, I didn't plan because I had the peachy notion that the story should have its own 'life' and that I wasn't truly creative unless I let it unfold itself as I went, and that, after all, I'm an author so I should be in my writing corner, my imagination buzzing, and the muse ... blah blah.
Now a few books on and hours and hours of editing / fixing (I could have written another novel in the time it took), I've embraced planning. Planning isn't the big monster that hinders creativity. On the contrary. Planning keeps the creativity on track and makes sure the picture works as a whole. More importantly, planning is a part of the creative process too. It's the act of creating a cohesive story skeleton. Once that skeleton is in place, I can create the muscle around it. . It's deciding which road I travel. To me it's like picking the size of the canvas to suit the painting I'm going to do. When I paint, I don't take a roll of canvas and keep going until I'm happy or have run out of surface. I have a fixed size. The frame. Now I'm free to be creative within it.
A plan for me could be a simple, beginning, middle and end, and deciding on motivation, goal, conflict, lessons learnt. It doesn't have to go into deep chapter by chapter detail. But at least I have signposts I know work.
And anyway, just because we have a plan before we start, doesn't mean it's set in stone. I can ditch the plan, or detour for bit if the story suddenly guides me that way.
