When The Buddha was asked if there is a self (an atta, an eternal self or soul), he remained silent. He felt the answer would not help his students understand his teaching.
What The Buddha did say was that anything you can identify is not self and he explained why, and that therefore nothing is worthy of being emotionally attached to.
This can be hard to understand, so here is an explanation:
Suppose you are calm and at peace.
Then someone comes over and says or does something that annoys you. Or something happens that upsets you.
Now you are upset. How did that happen? You didn't want to be upset. You liked being calm and at peace. You wanted to have equanimity and be indifferent to conditions.
Those unpleasant emotions are not under your control. They arise from somewhere unasked. Not by your intentional doing.
Most people consider the self to consist of their body and mind; thoughts and emotions. But if unpleasant emotions are not under your control, if they arise unasked for, not from your own intention, then how can they be "self"?
They are not self.
They are not yours. You don't control them. They come upon you unasked, unsought for.
When you see that, now you can let go of them. Those emotions are not yours, not you. Who cares about them?
This is the illusion that fools people.
They wonder "How can I let go of this unpleasant emotion?"
But they don't see that the very fact that they can't let go of it means that it is not self, not theirs, not worthy of being attached to.
It is like a magicians trick. A misdirection. The unpleasant emotions attract your attention so strongly and distract you from everything else, that you never think that they are not yours.
We all think, "I should be able to handle this without reacting emotionally." But that is the wrong view. That is the trap we all fall into. The right view is, "I can't control this so it's not me or mine." Then you don't care about the emotional reaction and it fades.
Another illusion involves craving. Craving is an unpleasant emotion that often goes unnoticed. We think getting what we want will make us happy but too often craving and chasing after things only makes us stressed, anxious, and unhappy. Seeing craving as not self can help you let go of it just like with other unpleasant emotions.
To see through these illusions, quiet the mind with meditation and observe what happens as unpleasant thoughts and emotions arise. When you notice an unpleasant emotion, craving, or an unwanted impulse, compulsion, obsession. or fixation, say to yourself, in a pleasant, relaxed, friendly way without suppressing or resisting it, something like:
Who asked for that? I perceive it so it's outside me. It's an illusion.
Self is the illusion that causes suffering and keeps us from seeing things as they really are.Unpleasant emotions tend to feed off themselves. When you are upset, you get upset that you are upset. It's like a feedback loop. Resisting emotions just reinforces the feedback loop with more unpleasant feelings. Rather than trying to suppress an unpleasant thought or emotion, react in a relaxed and pleasant manner. When you see that you did not try to make it arise, that it came unasked for, that you don't own it, that it is not yours, it is much easier to let go of. But old habits die hard, so you may have to repeat the process as the thoughts or feelings recur.
The way to develop equanimity, the way to become non-attached to external things, is by becoming non-attached to internal emotions because the way external things get to you is through the emotions you experience. When you are non-attached it does not mean you are indifferent. When you are not thinking about yourself, you feel more compassion for others not less.
If you are pure awareness just watching the universe unfold, nothing is good or bad, it is only when there is a self that things can happen in relation to that you can have unpleasant thoughts or emotions. When you meditate, notice the absence of mental chatter as you concentrate on saying the numbers while you count the breath or saying "in" and "out" while you inhale and exhale. Notice how peaceful that is and how pleasant that peacefulness is. When an unpleasant thought or emotion arises, try to see how it is the idea of self that that is at the root of the unpleasant feeling. For example, if someone annoys you, is it because their act offends your ego? If you want something, it is because not having it affects your status in the social hierarchy? Who wants? I want. Who likes? I like. Who doesn't want? I don't want. Who dislikes? I don't like. All attachments and aversions, liking and disliking, ultimately resolve to "self". But as we saw above, self is an illusion. Try to see how all unpleasant things resolve into problems caused by the illusion of self. If you are just pure awareness, just meditating on "in" and "out" there is no mental chatter, everything is peaceful and pleasant, there are no problems. But every time unpleasantness arises, self, appearing from nowhere, is at the root of it. Try to observe this transition between "non-self mind" and "self mind". See how the idea of self is always part of any unpleasant thought or emotion. And see how pleasant it is, after releasing the unpleasant thought or emotion, to return to non-self mind. As you do this, learn to abide more and more in non-self mind.