Thakur ji, how do you feel in samadhi?

Amrita (a devotee): "Thakur ji, how do you feel in samadhi?"

Sri Ramakrishna: "You may have heard that the keet (worm or moth or caterpillar), by intently meditating on the brahmara (wasp) , is transformed into a brahmara (wasp). Do you know how I feel then? I feel like a fish released from a pot into the water of the Ganges." 

Amrita: "Don't you feel at that time even a trace of ego?"

Sri Ramakrishna: "Yes, generally a little of it remains. However hard you may rub a grain of gold against a grindstone, still a bit of it always remains. Or again, take the case of a big fire; the ego is like one of its sparks. In samadhi I lose outer consciousness completely; but God generally keeps a little trace of ego in me for the enjoyment of divine communion. Enjoyment is possible only when 'I' and 'you' remain.

"Again, sometimes God effaces even that trace of 'I'. Then one experiences jada samadhi or nirvikalpa samadhi. That experience cannot be described. A salt doll went to measure the depth of the ocean, but before it had gone far into the water it melted away. It became entirely one with the water of the ocean. Then who was to come back and tell the ocean's depth?"

Source: Gospel of Sri Ramakrishna

Notes: 

'Bhamari' is also translated as 'butterfly', but more accurate is the 'wasp'. 'Keet' is the moth insect inside cocoon. Wasp makes humming sound while flying. It punctures the cocoon so that it can feed the moth. There are more than one hole. Through other holes, the wasp stings the moth. So the moth is constantly in fear of receiving the painful bite and also hopes of food. It constantly thinks of the humming sound of the wasp. Eventually, it gets transforms into the wasp. (It is similar analogy of caterpillar being transformed into butterfly.)   This analogy is very popular and is known as Keet-Bramar-Nyaya. 

Sri Ramakrishna says that upon constantly meditating on the object, which is God, one's mind gets absorbed in God and merges in God. One becomes God, but one still has little trace of ego so as to enjoy the communion and Bliss. This type of Samadhi is known as savikalp samadhi. Little bit of ego is needed to stayed connected with physical body. Later Sri Ramakrishna explains Nirvikalp Samadhi where there is not even a trace of Ego. Since there is no ego, there is no separate identity to experience the joy of communion. Hence such a state is inexplainable.