Acharya Prashant explains that the custom of adding 'Ji' to a name, while a social custom, has a profound spiritual basis, though it is now often corrupted. He states that many customs in India are meant to teach something in daily life. He breaks down a person's identity into three parts: the name, which refers to the physical self or body; the surname, which comes from ancestors and history, representing the mind; and 'Ji', which points to something more. Addressing a person merely by their name and surname is an injustice because a person is much more than their body and mind. The term 'Ji' is a vernacular form of the Sanskrit word 'Shri'. 'Shri' signifies all that is beautiful, abundance, auspiciousness, and fundamentally, the true Self, the Atma. Therefore, adding 'Ji' is a reminder that one is beyond the body and mind, referring to one's real essence. The speaker notes that this custom has largely become a dead, hollow practice, followed blindly without understanding its meaning. He contrasts the Vedantic approach with the Buddhist one. The way of Vedanta is to add 'Shri' (Ji) to the name and surname, offering a better identity beyond the body and mind. In contrast, the Buddha's way is to assert that the true self is nameless and formless, thus negating both name and surname. The intention of both paths is to show that one is not limited to the body-mind complex. Vedanta says you are not just the body and mind, while Buddha would say you are not the body and mind. Finally, he addresses the common use of 'Ji' as an affirmative, like saying 'yes'. He clarifies that this is a popular but not the originally intended usage. While one could interpret it as 'agreeing to the Truth' (since 'Shri' means Truth), this is a far-fetched explanation for its everyday use. The intended purpose is to acknowledge the true Self, which is beyond the material and will remain even after the physical body ceases to exist.