Explanation:
Malvolio believes Olivia is in love with him due to a series of misinterpreted events and his own inflated sense of self-importance. In the famous comedy, he misreads a letter written by Maria, which was meant to ridicule him, as a genuine declaration of love from Olivia. Blinded by his ambition and desire for power, he becomes convinced that Olivia’s supposed affections for him are real, leading him to display absurd behavior and indulge in grandiose fantasies of his newfound status.