solipsism - sol·ip·sism (sŏl′ĭp-sĭz′əm, sō′lĭp-)

n.
1. Philosophy The theory that the self is the only thing that can be known and verified.
2. The view that the self is the only reality.
3. Absorption with oneself without consideration for the needs and desires of others: a self-indulgent memoir that revealed the author's solipsism. https://www.thefreedictionary.com/solipsism