A devotee has genuinely got hallucinations about Lord Krsna interacting with him. After knowing the truth that its just hallucinations he is heart broken. How can he pacify himself and move on.
Then can it be considered as, Nothing happens by chance in this world. Not even a blade of grass moves without the consent of Lord Krsna.
According to previous Janma's Karma is he given that chance wherein Krsna trained that boy to chant Hare Krishna by watching the kirtanas.
IDT, can you please ask Chaitanya Charan Prabhu to explain about this psychosis mystery. It would be very helpful.