It is said that mind is a disease which keeps on playing constantly like a radio which knob is broken. We think it is repairable and in fact it is, we cannot stop it but the thoughts which are illusive, which are incorrect and which we term as maya, avidya, ignorance etc, these thoughts should be replaced by right ones.
Now what is right thinking? The creation theory of Srimad Bhagavatam says that from mahat tattva, ahankara (ego) this I is created. What is creation? Creation means something is created/thought which is mithya (not true). So to transcend creation and recognize eternity the final barrier is ahankara ‘I’, this I is to destroyed and to destroy this I ‘You” is to be created. But this creation of You is also a temporary measure because if I is not than you is also not. If there is no I then how can there be you, but this You is must to shift the attention from I. Without You there is no other alternative.
Now the problem arises when this You has to be discarded. It is very difficult as total faith is invested in this You. This has happened in Sri Ramakrishna Paramahansa’s life. He was a great devotee of goddess Kali and when he approached Totapuri the great Vedantist, the later adivses him to slit off the throat of goddess Kali. Hearing this Ramakrishna was terribly shocked and tears starts flowing from his eyes; how is it possible, mother whom I have loved and worshipped for my entire life, how is it possible. But there is no way out says Totapuri you have to do it. For a week Ramakrishna tried but it seems impossible for him. Totapuri was a strict man and he warns that if you cannot than I am leaving. Sri Ramakrishna says how is it possible where shall I find the sword, create it from your imagination from where you have created your mother, says Totapuri. It is a long story but at the end Ramakrishna succeeds.
So to recognize eternity the last barrier which is ahankara, which is I is to be destroyed and for that purpose You has to be created which is also temporary and after destruction of You what remains is That ‘Tat Twam Asi’ (you are that), I and you merges into that.