Why do writers usually use first person point of view in personal narratives?

Answer 1

I'm not sure if this is the answer you're looking for, but, an author might choose a first-person narrator to create a greater sense of intimacy between the narrator and the reader. In first-person narration, the main character is essentially speaking directly to the reader: "I went down the stairs and saw my mom crying on the couch. She didn't see me, so at first I just stood there, wondering what to do. I knew she was crying about Dad leaving, but I didn't know what to say to comfort her," for example.

In a third person narration, the character's thoughts and feelings are relayed to us by the narrator, instead of by the character himself. Essentially, the narrator is like the middle man, conveying the character's thoughts and feelings to us: "She went down the stairs and saw her mom crying on the couch. Her mother didn't see her, so at first she just stood there, wondering what to do. She knew her mom was crying about her dad leaving, but she didn't know what to say to comfort her." Instead of the character telling us this, it's the narrator who's telling us.

Third person omniscient narration is when the story is told from more than one character's point of view. For example, instead of just hearing the daughter's point of view, we might hear the mother's as well: "She went down the stairs and saw her mom crying on the couch. Her mother didn't see her, so at first she just stood there, wondering what to do. She knew her mom was crying about her dad leaving, but she didn't know what to say to comfort her. Susan looked up and saw her daughter standing there watching her. For a brief moment, she felt embarrassed, and resentful of the intrusion. But then she saw the pain in her daughter's eyes, and she knew they were both hurting from her husband's sudden absence."

There are times when the third person can be almost like the first person. Sometimes, even though the characters are referred to as "she" and "her" instead of "me and "I" it still feels as though we are inside the character's mind, instead of having the character's thoughts relayed to us by a narrator. This effect is much harder to achieve with third person omniscient narration. Since the perspective is constantly changing, it's harder to build a bond of intimacy between each character and the reader. It's easier to build a bond of intimacy when we stay inside one character's head the whole time.
To help the reader identify with the narrator.

If they were writing in the style of a diary.

The use of first person makes it easier for composers to convey humor in a text. First person makes the text more personal, thus making it easier for the composer to persuade the audience.

First person puts you inside the narrator's head. It's easier to identify with the narrator and know what he or she is thinking with first person POV, and often it's more exciting to view the story this way instead of as though you were watching a movie, as with third person.
First person is more immediate and allows the reader to get inside of the narrator's head better than third person.

Answer 2

To let the reader become close to the narrator

Answer 3

It just makes more sense when telling a personal story.