From Longman Dictionary of Contemporary Englishthink the best/worst of somebodythink the best/worst of somebodyAPPROVEto consider someone’s behaviour in a way that makes them seem as good as possible or as bad as possible He’s determined to think the worst of me. → think
Examples from the Corpus
think the best/worst of somebody• The prospect of Guy leaving, thinking the worst of her, was unbearable.• I was so ready to think the worst of him, she wailed inwardly.• Why should you think the worst of me?• You always think the worst of me.• He thought the worst of Mitch and clearly thought that left to herself she would ring London at once.• Ellie's the type of person that always thinks the best of people.• My immediate reaction, whether it be a man or a woman, is to think the worst of them. 