There are many ways we use the term "self" and not all of these selves are illusory. I can talk about myself in terms of my personal history or with respect to my location as a body and physical space. I can think myself in various social roles, as a writer or as a father or as a customer in a store.
And there's nothing wrong with thinking about ourselves in these terms. Most of this is unavoidable. There is however one sense of self that is confusing and that produces a tremendous amount of unnecessary suffering for us. And happily this sense of self can be dispelled through meditation. It can be discovered to be illusory through meditation.
And this self is the feeling in each moment that we are subjects internal to our bodies. The feeling of being inside our heads. It's almost as though we feel that we're passengers in our bodies and it's this feeling that is also referred to as the ego. You feel, like most people, what you are calling I is this feeling of being the internal subject of your experience. I does not refer merely to the body and it certainly doesn't refer to the totality of experience. I appear to be the center of experience. It's that which has appropriated experience. Now this feeling that we call I is itself the product of thought.
Having an ego is what it feels like to be thinking without knowing that you're thinking. It's the feeling of being identified with thought. Imagine that you run into someone you know and like a lot and when they see you, rather than smile as they usually would, they look very unhappy.
And the first words out of their mouth are "I can't believe you would do that". Now assuming you have no idea what they're talking about. So your first thought is "What? What did I do?" Now imagine your friend looks at you with real mistrust and says "Seriously?". And all you can think at that moment is "What, what did I do? What are you talking about?"
Now, these are just thoughts, and yet they completely subsume you, they seem to be what you are in each moment of their horizon. You have no perspective on them. There's no space around them. Your consciousness has been almost entirely reduced to a string of sentences and to the feeling of urgency that created them and which they create in turn.
But how could you actually be a thought, how could consciousness be trimmed down to a sentence? whatever their content, thoughts vanish almost the instant they appear. They're like sounds or sensations in the body. How could this next thought, however urgent, define consciousness at all? Consciousness is the prior condition of its arising.
It's the state of being identified with thought, of there being no space, no perspective, where each thought is just you, "what, what did I do?". Thoughts are arising in each moment and you don't even know that you're thinking. It's like dreaming when you're asleep and you have no idea that you're dreaming.
That experience, a full capture by the contents of consciousness, is the ego. It is the self that is the target of deconstruction by the practice of meditation and this self is a burden even when things seem to be going well. Consider the feeling of pride - let's say you've just done something great and you've been praised for it in high places - how good does that feel?
You know the feeling, some part of your mind is just lapping it up with its little cat's tongue. But this is the same part of you that is always poised to be miserable, this is the part of you that's always comparing yourself to other people. This part of you, even when it's riding along at full gallop, can be unhorsed with a single sentence or even a glance. The rewards of the ego are not good enough and again, we're just talking about patterns of thought, one thought following the next.
And the selflessness that can be realized through meditation is not a deep feature of consciousness, it's right on the surface and yet people can meditate for years without recognizing it. How can something be right on the surface and yet be difficult to see? Well consider the optic blind spot by analogy, you've probably been shown this in school, where you closed one eye and then stare at a fixation point on a piece of paper and then you're asked to notice that a dot in the periphery of your visual field disappears when you're just the right distance from the paper.
If you close one eye now there's certainly something in your visual field that falls into your blind spot and you don't notice it and surely most people in human history have been totally unaware that the blind spot even exists and many of us who know about it go for decades without thinking about it, much less noticing it.
The absence of the self is also there to be noticed. As with the blind spot, the evidence for it is not far away or deep within. It's almost too close to be observed. And for most people, experiencing the absence of self requires considerable training, and that's what we're doing here.
Okay, it is possible to notice that consciousness, that in you which is aware of your experience in this moment, does not feel like a self, it does not feel like I, rather whatever feels like I is itself another appearance in consciousness. Whatever you can feel is being known by this prior condition, which we're calling consciousness or awareness.
How can we know that the conventional sense of self is an illusion? well the most compelling way is to get yourself into position to really look for it and then find it absent and that's the point of meditation. When you really look for this thing that feels like I, it vanishes.
And this is compelling in the same way that the disappearance of any illusion is compelling. You thought something was there but upon closer inspection you can see that it isn't. Okay, in this case you can feel and know that it isn't. There's a general intellectual and epistemic principle that work here, whatever is there when you're paying the closest attention stands a better chance of being real than what seems to be there when you're not paying attention.
What doesn't survive scrutiny cannot be real. Now as you get further in the practice of meditation, you will discover that there is no thinker apart from your thoughts. There's no one producing these thoughts. And there's no one receiving them, there's just consciousness and its contents as a matter of experience.
There's no one who's choosing the next thing you do. Thought and intention and choice just arrise and become effective or not based on prior causes and conditions. the feeling that you are in the driver's seat able to pick and choose among thoughts is itself a thought that has gone unrecognized.
This feeling of being a self that can pick and choose is what it feels like to be thinking without knowing that you're thinking.