Bepin Babu lost consciousness at Hundroo Falls that made him unconscious. What do you think was the reason for this?

Bepin Babu went to visit Ranchi after his doctor Paresh Chanda asked him to do so in order to stoke his memory of going to Ranchi in 1958. After going there Bepin Babu realized that the station, the streets, the bazaar and everything else seemed new to him. Not a single memory of any kind came back to him. Unwilling to leave any stone unturned, he also went to the Hundroo Falls and realized his last hope was extinguished and no memory was ever coming back to him again. This realization along with the fact that his brother was an insane person, made him sick being the reason for Bepin Babu’s unconscious at Hundroo Falls.