Okay, so. I used to be an inveterate pantser. Usually, nowadays, I plot. Mostly because there's far less desire to defenestrate my computer.
We are all voracious readers, here, right? That means we know wholly by instinct how Story is supposed to work. My first novel, I wrote completely by accident, no lie. I had a vague setup in my head, and the first chapter made the rest of it inevitable. I didn't know that at the time, of course, and it wasn't until I was 25,000 words into it that I was willing to use the n-word--no, not that one. "NOVEL." *shudder* I had no idea how that sucker was going to end and didn't even realize who my main protagonist was until I was deciding whether or not he was going to die (again) about 70,000 words in. WHEE. It was kind of exhilarating.
But when I went back and retroactively wrote up a synopsis for it, I found that I'd instinctively used the seven-point plot structure, before I even knew what that was or why it was useful. We. Know. Story. It's hardwired.
Now, figuring out the most efficient way of getting Story from our brain to the page can be an issue. Writer Brain is funny. Pantsing gives you that "Ohmygosh, what happens next" kick, but waiting for inspiration to strike--or, worse, getting absolutely stuck because you've written yourself into a corner--is super frustrating. I can't tell you how many times I had to yell at my characters to TALK TO ME DAMMIT. Sometimes they complied. And sometimes I had to replace a computer and a window. For me, having it be the last thing I thought about at night and the first thing I thought about upon waking, and then having inspiration strike in the shower, was very common. And still is, for that matter, even with an outline. Sometimes going for a walk, or talking it over with someone, or a change of scenery also helps.
Plotting means you don't have to wait for inspiration. You know what happens next, yay! All you have to do is write it. The words flow from your keyboard like a waterfall. And then lay there on the page like a dead carp. You know what happens next? Then why bother writing the thing at all? Where's the joy of discovery? Oh, hey, that cool idea you just had? Sorry, Charlie, it won't fit and furthermore totally messes up everything else you've planned meticulously from here on out. Pop it in the Plot Bunny Hutch; maybe you can use it later in something else.
Orrrr... Incorporate it and re-do your outline. Because one mistake a lot of plotters make is thinking their outline is written in stone. It's not. That cool new idea might be just the thing to breathe life into your dead carp. That being said, don't discard the original outline, because that cool new idea might also be one that derails the whole thing into the tall grass. There's gators and rattlers in there. Be careful, and realize that you can also discard that cool new idea if it means you've got venomous snakes snapping at your butt.
Keep in mind that the magic of writing happens in edits. If you're pantsing, you can go back and insert all that neato foreshadowing you didn't know you needed, and people will think you're brilliant. Those dead-carp words you outlined so carefully, that are now just lying on the page? You can edit those into beautiful goldfish. You can't edit a blank page.
The Cardinal Rule of Writing is:
Do what works for you.
Scratch 20 writers, you'll find 30 processes. Sometimes a process that works great with one project completely falls apart with another. And that's okay and perfectly normal.
BE FLEXIBLE. TRY EVERYTHING.