Nenjai Thodu

Nenjai Thodu is a South Indian Tamil film released in 2007.

When both Siva and Aishwarya were travelling in a train, they come to know that bomb is fixed in a train. All the passengers had came out, the train gets crashed which makes both Siva think that Aiswarya is dead while Aiswarya assumes that Siva is dead, they both fall unconscious and admitted to the hospital. It is revealed that Sivas mind has damaged doctor reveals that since his mother died his mind has become emotional and he is under the wrong impression that Aiswarya is dead. The film ends with Sivas father and Aishwarya taking care of Siva but it is revealed that Sivas mind will become normal only after four or five months.

Source: Wikipedia