Thinking in 3rd person...

In grammar terms, person goes like this
I is first person
you is second person
he/she/it is third person.

And most professional writing only includes the third person pronouns. We tell our students not to write about how "I feel" or what "you should do."

When they complain, I simply tell them that we do this to make their papers sound more convincing. I say, "it puts the focus on your ideas, rather than you as a person." I say that it makes the writing more convincing.

but that's not the truth.

The truth is that we make people write in the way we do, because we want to change the way people think.

We make people write in the third person because we want them to think in the third person.

We want students to wonder what evidence they have for their beliefs. We want them to think about the opinions of those that disagree. We want students to think objectively, apart from emotions, feelings, hunches, and intuitions.

Unfortunately, we cant do that. So we settle for teaching them to write in the third person.