One of my students raised an interesting question in class about point of view, something that seems to come up in one way or another every class session. This time it was about first person. "I couldn't figure out whom this 'I' person was telling the story to," he said during a critique session. Then the following week, we had a story that was an actual monologue, purporting to be told directly to an FBI agent, but in some ways this only muddied the waters further, since no one telling a story to another recites whole long exchanges of dialogue word-for-word. "I don't see why you just couldn't tell this story in third person," said another student.
To some extent, all first-person narratives are artificial -- even more artificial than other fiction, and for the reasons given above. No one does recite, or even write, to another person such long scene-by-scene stories that include detailed exchanges of (to name just one element) other peoples' dialogues. This is why the first novels in English were epistolary (Pamela), written as exchanges of letters between characters, or else pretended to be diary entries (Robinson Crusoe). But as the form evolved, that proved to be too limiting. So the first-person-narrative-told-to-no-one-in-particular-and-in-artful-detail came to be accepted as a convention, and now no one except thoughtful writing students wonders at this.
I like first person. Even though it limits the scope of the action (your narrator must be present in order to include the scene), I like the freedom it gives to roam around every corner of my protagonist's head, as well as to saturate the prose with his peculiar diction. My current project, a long YA fantasy, is in first person. So, it turns out, is nearly every story I've written that has won an award (the one exception is "Beggars in Spain.") Perhaps some writers just have a built-in affinity for a specific point of view. If so, then I -- like my sister, the professional actress -- really like to spend months of work time being someone else.