The phrase "lost in" often describes the feeling of being disoriented or confused. Some synonyms for this phrase include bewildered, perplexed, discombobulated, flustered, and befuddled. These words all convey a sense of being unable to comprehend or make sense of one's surroundings. Other synonyms include distracted, preoccupied, and absent-minded, which suggest a lack of focus or attention. Additionally, one could use the terms absorbed, engrossed, or immersed to describe being fully immersed in something to the point of losing oneself. Overall, there are many different ways to describe the sensation of being "lost in" something, each with its subtle nuances and connotations.