Ahaṅkāra. Ahaṅkāra means my identification, what I am. That is called ahaṅkāra. Now my identity is with this material world. "I am Indian," "I am American," "I am this," "I am that." That should be negativated. We must come to the right conclusion that "I belong to Kṛṣṇa, I am the son of Kṛṣṇa, I do not belong to anyone." This is called nirahaṅkāra. Sama-duḥkha-sukhaḥ. This material happiness and distress. Because I am not this material body, if I am actually convinced, so the pains and pleasure of this material world is due to this body.
Just like because I have got this material body, I am feeling some heat. Therefore fan is required. Similarly, by this body in the winter season I shall stop the fan. So under different season my body feels differently pains and pleasure. But actually, if I am not this body, then I should tolerate all these pains and pleasures. This is called sama-duḥkha.