Realisation of one's oneness with the entire manifestation is a true sign of a Jnani.
Once a sadhu who was drunken with intoxication of God came to the Kali temple. One day on not receiving anything to eat, the sadhu found a dog eating the remnants of a feast cast away in the corner. He at once approached the dog and hugging it said, “Brother how is that you alone eat without giving me a share?” Saying so he started partaking of the food with the dog. After his meal, he came to the temple and prayed to Mother Kali with ecstasy. After having finished His prayer, when he turned to leave, Sri Ramakrishna sent Hriday to follow the Sadhu and make conversation with him(Sadhu) and report his to Him is words.
The Sadhu on seeing Hriday asked the reason for his following. Hriday beseech ed the Sadhu to impart spiritual teaching to him. The Sadhu told Hriday, “When the water of this ditch and the water of the Ganges appear to be the same to you, and when the sound of this flageolet and the noise of the crowd there makes no difference to you, then you will attain true knowledge”
Hriday reported the words of the Sadhu to Sri Ramakrishna. Sri Ramakrishna immediately acknowledged the Sadhu to have attained the true state of knowledge.
Sri Ramakrishna remarked that true Jnanis or realised souls wandered about like guileless children, mad men and ghouls with their actual state camouflaged in their outer peculiarities.