Why is winston considered a lunatic in Part 3 of 1984?

In Part 3 of George Orwell's 1984, Winston is considered a lunatic primarily because he refuses to conform to the Party's ideology after enduring intense psychological and physical torture in the Ministry of Love. His obsession with truth, individuality, and his past memories starkly contrast with the Party's enforced beliefs, leading him to express thoughts that are deemed irrational and rebellious. Additionally, his inability to accept the Party's absolute power and his longing for freedom make him appear insane in a society that prioritizes conformity and blind loyalty.