When person becomes free of desire, longing, sense of ‘mine’ and ‘me’, he experience sustaining state of peace in him. The root cause is the ego or sense of ‘I’. After letting go of all other things, the ego still remains. Once the sense of ego (‘I’) goes then it is possible to let go of everything. From ego ensues fondness, from fondness the attachment, from attachment, Mamatā (sense of mine-ness), from Mamatā the desires arise, from desire many other modifications come about. For a spiritual seeker, it is easier to leave Mamatā first, after leaving Mamatā, one can get the strength to renounce desire, longing and Ahmtā (ego). In fact, we are without the desire, longing, Mamatā and Ahmtā. If we were not without these attributes then we could never leave these and the Lord would not have brought up the idea of giving up these. During the deep sleep, everyone experiences the absence of Ahmtā but no one experiences the absence of Self.
The truth is that the desire, longing, Mamatā and Ahmtā are unreal and do not exist ‘nāsto vidyate bhāvo’ (Gītā 2/16) ‘The unreal has no existence’. Our true nature is real, luminous Self. In this real Self, the question of having the desire, longing, Mamatā and Ahmtā does not arise. The desires etc. reside in the Jada (worldly matter), they cannot reach the Cetana (consciousness). The existence of consciousness stays the same. The desire, longing etc. do not remain at all times, they are constantly changing– this is the experience of everyone. In this life, in childhood the desire and longings were different, now they are different. We continue to pick these up and leave them as we move into different stages of life. We used to have the desire for toys, then, started to have the desire for money. First there was Mamatā (affection) for the mother, then, this affection shifted to wife. Thus the desire, longing, Mamatā etc. are coming and going, also, the meeting and parting, beginning and end happens but the Self does not come or go. The thing which is not truly real we got hold of, gave importance to its existence, this is biggest mistake we have made. The responsibility of correcting this mistake lies with us only, that is why Lord Kṛṣṇa is asking us to make the correction. Otherwise the thing which does not truly exist, to leave that is natural. What is real, that is the thing to be attained. There is nothing new to be done, going after something new is the reason for the bondage and suffering.