There are many symptoms of ecstatic love caused by remembering Kṛṣṇa. For example, one friend of Kṛṣṇa informed Him, "My dear Mukunda, just after observing a bluish cloud in the sky, the lotus-eyed Rādhārāṇī immediately began to remember You. And simply by observing this cloud She became lusty for Your association." This is an instance of remembering Kṛṣṇa in ecstatic love because of seeing something resembling Him. Kṛṣṇa's bodily complexion is very similar to the bluish hue of a cloud, so simply by observing a bluish cloud, Śrīmatī Rādhārāṇī remembered Him.
One devotee said that even when he was not very attentive he would sometimes, seemingly out of madness, remember the lotus feet of Kṛṣṇa within his heart. This is an instance of remembrance resulting from constant practice. In other words, devotees who are constantly thinking of the lotus feet of Kṛṣṇa, even if they are momentarily inattentive, will see the figure of Lord Kṛṣṇa appearing within their hearts.
Argumentativeness
Madhumaṅgala was an intimate friend of Kṛṣṇa coming from the brāhmaṇa community. Kṛṣṇa's friends were mostly cowherd boys belonging to the vaiśya community, but there were others who belonged to the brāhmaṇa community. Actually, in Vṛndāvana the vaiśya community and the brāhmaṇa community are considered prominent. This Madhumaṅgala one day addressed Kṛṣṇa in this fashion: "My dear friend, I can see that You are not aware of the peacock feathers that are falling on the ground, and at the same time You are unmindful of the flower garlands which are offered to You. I think I can guess the reason for Your absent-mindedness when I see Your two eyes flying over to the eyes of Śrīmatī Rādhārāṇī, just like black drones flying to lotus flowers." This is an instance of an argumentative suggestion in ecstatic love.