Patanjali Yoga Sutra 2.5

Avidya is taking the impermanent as permanent, the impure as pure, pain as pleasure, and non-self as self.

अनित्याशुचिदुःखानात्मसु नित्यशुचिसुखात्मख्यातिरविद्या ॥

anityasuci-duhkhanatmasu nitya-suci-sukhatma-khyatir avidya ||

Avidya is taking the impermanent as permanent, the impure as pure, pain as pleasure, and non-self as self.

A vidya (ignorance) has absolutely nothing to do with lacking formal education or a university degree. It is a fundamental cognitive distortion—four specific "mis-seeings" that drive human psychological suffering. First, we take the impermanent as permanent: a temporary depressive mood or wave of panic is treated as if it will last forever. Second, we take the impure as pure: a deeply harmful, toxic relationship or environment is treated as sacred and necessary. Third, we take pain as pleasure: a self-destructive, numbing habit or addiction is treated as genuine emotional relief. Fourth, we take the non-self as the self: a temporary social role, a fleeting emotion, or a clinical diagnosis is treated as the absolute entirety of a person. In modern Cognitive Behavioural Therapy (CBT), these mis-seeings map perfectly to deeply rooted core beliefs and severe overgeneralisations. True recovery begins when we correct our internal vision and finally see our thoughts, habits, and identities exactly as they are.