That is stated in the Bhagavad-gītā, that we have to try to remember Kṛṣṇa. He's so beautiful, His instructions are so nice. If we simply remember Kṛṣṇa... That was the perfection approved by Lord Caitanya. I think I have narrated the story.
When Lord Caitanya was traveling in South India in a big temple, Raṅganātha temple, He went to see the Deity, and He saw one brāhmaṇa was reading Bhagavad-gītā. And people were joking him, "Oh, Mr. brāhmaṇa, how you are reading Bhagavad-gītā?" Because they were the neighbors, they knew that this brāhmaṇa was illiterate and he was
studying Bhagavad-gītā. So they were joking. But the brāhmaṇa did not care them. He was taking the book and in his own way he was reading.
Caitanya Mahaprabhu saw this incident, He came to the brāhmaṇa. So He asked the brāhmaṇa,"My dear brāhmaṇa, what you are reading?" So he could understand "This persons is not joking with me; He is serious." So he explained, "My dear sir, I am reading Bhagavad-gītā.Unfortunately, I am illiterate. I do not know even the alphabets." "Why you are reading Bhagavad-gītā?" So he said that, "My spiritual master knows that I am illiterate, but still, he has asked me to read Bhagavad-gītā. What can I do? Therefore I have taken this book. I am seeing simply. I do not know how to read." "Oh, that's all right. You cannot read. But I see that you are crying. How you are crying if you are not reading?" "Yes, I am crying. Of course, there is cause." "What is that?" "As soon as I take this Bhagavad-gītā, I remember Kṛṣṇa. Kṛṣṇa is sitting as driver and Arjuna is hearing. I have heard the story. I know something of the instruction but cannot read. So as soon as I take this book, this picture comes before me and I simply think, 'Oh, how Kṛṣṇa is nice that He has become a charioteer of His devotee. He is so great. Still, He has accepted a menial service of His devotee.' This gives me so much pleasure that I cry."
Caitanya Mahāprabhu embraced him, "Your Bhagavad-gītā reading is perfect. You have taken the essence."
So this is the thing. If you simply remember Kṛṣṇa is teaching Arjuna and Arjuna is hearing, if you simply remember the picture, that is sufficient. Even if you think that you cannot read.
Because after all we have to become Kṛṣṇa conscious. We haven't got to become a learned man to argue with another learned man. If it is possible we can do that, but that does not make any difference if I cannot argue with others or if I cannot teach very nicely Bhagavad-gītā to others. Simply if I remember this picture, that is perfection. Because we have to become Kṛṣṇa conscious. We have to simply think of Kṛṣṇa. You think in any way. That is your perfection. Smartavyaḥ satataṁ viṣṇuḥ. This is the injunction. You have to think of Viṣṇu always. This is samādhi; this is meditation; this is yoga siddhi, perfection of yoga.
(Srila Prabhupada's Bhagavad-gita Lectures – Los Angeles, November 25, 1968)