Solipsism

Solipsism ( SOLL-ip-siz-əm; from Latin solus ‘alone’, and ipse ‘self’) is the philosophical idea that only one’s mind is sure to exist. As an epistemological position, solipsism holds that knowledge of anything outside one’s own mind is unsure; the external world and other minds cannot be known and might not exist outside the mind.

wikipedia/en/Solipsism

the view or theory that the The Self is all that can be known to exist.

“Solipsism is often introduced in the context of relating it to pathological psychological conditions. Austrian neurologist Sigmund Freud stated that other minds are not known, but only inferred to exist, he stated “consciousness makes each of us aware only of his own states of mind, that other people, too, possess a consciousness is an inference which we draw by analogy from their observable utterances and actions, in order to make this behavior of theirs intelligible to us. (It would no doubt be psychologically more correct to put it in this way: that without any special reflection we attribute to everyone else our own constitution and therefore our consciousness as well, and that this identification is a sine qua non of understanding).”

One who sees everything as nothing but the Self, and the Self in everything one sees, such a seer withdraws from nothing. For the enlightened, all that exists is nothing but the Self, so how could any suffering or delusion continue for those who know this oneness? — wikipedia/en/Ishopanishad: sloka 6, 7