I've encountered a lot of people who say the following:

"Of course I have a self! I have a unique first-person perspective on the world. I am the only one who thinks my thoughts and feels my feelings. I don't have access to your thoughts, and you don't have access to mine, and we don't see the world the same way, so that proves that you and I both exist."

This is a fallacy.

Let's take it apart bit by bit.

1) A unique first-person perspective on the world.

Not to be too blunt about this, but heck, mate, what else can a human body generate?

Can you conceive of eyes that see in second or third person? How about ears that hear in second or third person? Maybe your skin should feel things that push that guy over there instead of things that push the body that skin is part of?

Ditto uniqueness. If my body is standing over here and your body is standing over there, of course their perspectives would be unique. The only way two bodies could have the same perspective would be if they overlapped so completely that they were, in fact, the same body. Do you see that happen a lot?

A unique first-person perspective on the world is the natural, inevitable, and automatic consequence of there being a body with a set of senses. Nothing more.

2) I am the only one that thinks my thoughts and feels my feelings. I don't have access to your thoughts, and you don't have access to mine.

First off, there is no you that thinks thoughts and feels feelings. Look for one in your experience. Can you see the thinker or the feeler? Can you see anything other than the thoughts and feelings themselves? Do they need you to do something before they arise?

Secondly, think about what it means for a human body to function again. Is a human body equipped with senses that let it feel another body's physical pain? Is it equipped with senses that let it feel another body's digestive processes? How about ATP synthesis? How about another body's sense of smell, or taste, or touch?

Then why would one human body be able to sense another's thoughts or feelings?

The fact is that one human body is incapable of directly experiencing the same thing as another human body because of basic facts of biology. A self is not required to explain it.

3) We don't see the world the same way.

From the point of birth, no two human bodies occupy the same physical space. They are usually not even genetically the same, so they come with starting differences. Either way, they will always encounter different stimuli from the environment, and those stimuli will cause the development of different cognitive frameworks in response, and thence the thinking of different thoughts and the feeling of different feelings.

Thinking and feeling in different ways is a natural, inevitable, and automatic consequence of being different people.

So do unique human beings with unique first-person perspectives on the world and unique thoughts and feelings that cannot be directly experienced by another exist? Yes.

Is a self necessary for them to be any of those things? No.

Does a self exist? No.

Look. You can see this for yourself, in your own experience.