Do you feel like you've lived this same day many times before?
what is this effect called?

Déjà vu

Explanation:

Déjà vu is the feeling that someone has experienced a particular feeling before but cannot recollect what exactly that was or when it happened. It happens occasionally or when a person has undergone stress or pressure.

When the feeling occurs more regularly it is advised to seek medical help as the individual's mental health might be compromised and is now indicative of severe conditions.

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