The old words for it are everywhere, once you know what you are looking at.
India called it maya — the veil, the magic show, the rope mistaken for a snake at dusk. The Buddha called the mistaken self a bundle of borrowed threads with no weaver inside, and called the ache it produces dukkha — a wheel riding off-center, grinding on every turn. The Hebrew story put it in a garden: one bite of the knowledge of separation — this is good, that is evil, I am this, not that — and suddenly the humans are hiding, ashamed, exiled east of Eden. Not killed. Exiled. The garden goes on without them, close enough to ache for. Jesus talked of the lost son who travels to a far country and starves there, feeding pigs, dreaming of his father’s table — and the far country is not a place; the father’s house was never more than one remembering away. The Sufis say the lover is searching the world for the beloved while the beloved is looking out through the lover’s own eyes. China simply said: people have forgotten the Way, like fish who have forgotten water and are dying of thirst.
Veil. Exile. Forgetting. Dream. One diagnosis, many accents.
Notice what the diagnosis is not. It is not that you are wicked, or broken, or insufficiently improved. Every tradition’s outer crust eventually says something like that, because guilt fills temples. But at the core, no one is angry with you. You cannot be guilty of dreaming. The diagnosis is gentler and stranger than guilt, and much harder to sell: there is nothing wrong with you that waking would not end, and nothing missing that was ever truly missing.