There are a variety of synonyms for the phrase "lost one reason", each reflecting a slightly different connotation or emotional tone. Some possible alternatives include "befuddled", "confused", "disoriented", "perplexed", "bewildered", "discombobulated", "unmoored", "adrift", "bewitched", "distracted", "foggy", "muddled", "stupefied", and "unsettled". Each of these terms captures a sense of mental or emotional disorientation, whether caused by external factors or internal confusion. Depending on the context, one synonym may be more appropriate or effective than another in conveying the intended meaning or evoking the desired emotional response.