The phrase "blew one's mind" is a popular expression used to describe an experience or moment that is so astonishing or incredible that it overwhelms one's perception, understanding, or expectations. However, if we were to look for antonyms or opposite words for this term, we could use words like mundane, unremarkable, unexciting, or ordinary. These words suggest the lack of surprise, novelty, or significance in a situation, indicating that nothing extraordinary or noteworthy happened. Another antonym for "blew one's mind" could be "underwhelmed," which implies a feeling of disappointment or dissatisfaction with something that falls short of expectations or fails to impress.