Most writers treat point of view like a setting on a camera. You choose first person or third person the way you'd choose a lens, and then you start shooting. Ursula K. Le Guin had a better way of thinking about it. She wrote that POV isn't the camera. It's the steering wheel. It determines where the story can go, what rooms it can enter, what it's allowed to know. Change the point of view and you don't just change the voice. You change the architecture of the whole book.
I think most of us understand this on some level, but we don't really feel it until we've written the same scene twice in different POVs and watched the story become a different story entirely. The information shifts. The emotional center of gravity moves. Sentences that worked perfectly in first person fall apart in third, and scenes that felt flat in third suddenly have weight in first.
A few things worth knowing about how that decision actually works.
1. First Person Chooses a Witness, and That Witness Is the Story
When Fitzgerald wrote The Great Gatsby, he didn't write it from Gatsby's point of view. This is probably the most consequential structural decision in twentieth-century American fiction, and I think it gets taught backward. The usual explanation is that Gatsby needs to remain mysterious, which is true, but it misses the deeper reason.
Nick Carraway is the point of view character because the novel is about what it feels like to watch someone believe in something completely. Gatsby's faith in the green light and in Daisy, his whole conviction that you can repeat the past if you want it badly enough, all of that only becomes meaningful when filtered through a narrator who is simultaneously drawn to that faith and skeptical of it. Nick wants to believe the way Gatsby believes. He can't. And the tension between those two positions, the yearning and the doubt, is the actual story of the book.
If Gatsby narrated his own story, you'd get a different novel. Maybe a good one. But you'd lose the specific thing that makes The Great Gatsby work, which is the experience of watching devotion from the outside and not being able to decide whether it's beautiful or delusional. Nick can't decide. The reader can't decide. That irresolution is the point, and it only exists because Fitzgerald chose a witness who is close enough to care and far enough away to wonder.
This is what first person point of view does at its best. It doesn't just show you the world through someone's eyes. It makes the narrator's specific way of seeing into the subject of the book. Every first person narrator is, in a sense, telling you two stories at once: the story of what happened, and the story of who they are for telling it this way.
2. Third Person Asks More of the Writer Than Anyone Expects
There's a tendency, especially among newer writers, to think of third person as neutral. As if it's the absence of a choice. You write "she walked into the room" instead of "I walked into the room" and that's about it.
George Eliot would have found this amusing. Middlemarch is written in third person omniscient, and the omniscience functions as a presence with opinions, one that makes philosophical observations about marriage and ambition and provincial life that no single character in the novel could articulate. Eliot's narrator moves between characters' inner lives with a freedom that first person can't touch, entering Dorothea's idealism in one chapter and Lydgate's professional vanity in the next, and the movement itself becomes an argument about how human beings misunderstand each other because they can't do exactly what this narrator can do, which is see into more than one consciousness at the same time.
Third person omniscient, the way Eliot practices it, is a commitment to knowing more than any character knows, and then using that knowledge to create a specific kind of sympathy. When you can see that Dorothea and Casaubon are both suffering in their marriage, each convinced the other person is the problem, and each partially right in ways they can't recognize, you arrive at a compassion that neither character can feel for the other. The narrator creates it. The reader receives it. And the gap between what the reader understands and what the characters understand becomes the moral texture of the entire book.
That's a very different thing from a camera. That's an intelligence at work.