When one understands fully this, I mean to say, fact, that spirit soul is different from this material world, then he's actually learned. In that stage he's called situated in brahma-bhūtaḥ stage. The symptom of brahma-bhūtaḥ is brahma-bhūtaḥ prasannātmā (BG 18.54). As soon as one becomes self-realized, he becomes jubilant, jolly. So long one identifies with this body, he is unhappy, full of anxiety.
So Bhagavad-gītā begins with this point, that one should know that he is not this material body. That knowledge is lacking at the present moment throughout the whole world. Yes. Everyone is identifying with this body like the animals. Therefore Kṛṣṇa chastised Arjuna that "You have got animalistic concept of life and still speaking like a very learned scholar. No learned scholar laments on account of this body." It is said in the Bhagavad-gītā, dhīras tatra na muhyati (BG 2.13). Dhīra... Dhīra means one who is sober by education.