Devotee or Guest: I want to ask you how can we possibly know that one has attained Kṛṣṇa consciousness.
Prabhupāda: You have to think of Kṛṣṇa. Hm? What did he say, question?
Hṛdayānanda: He wanted to know what are the symptoms of one who has become Kṛṣṇa conscious.
Prabhupāda: Symptoms? He's chanting always Hare Kṛṣṇa. Unless one is Kṛṣṇa conscious, why he'll take the trouble, twenty-four hours, "Hare Kṛṣṇa, Hare Kṛṣṇa, Hare Kṛṣṇa, Hare Kṛṣṇa"? This is the symptom. The symptom is further explained that as soon as you see one man and you remember Kṛṣṇa, that means he's Kṛṣṇa conscious. So our men, wherever they go, people say, "Hare Kṛṣṇa!"—by seeing him only. Therefore the man is Kṛṣṇa conscious. This is the proof. That is the statement of Caitanya Mahāprabhu, "If by seeing one person you remember Kṛṣṇa, that person is Kṛṣṇa conscious."