The phrase "lost sight of" typically refers to the act of forgetting something that was once important or losing focus on a particular goal or objective. There are several synonyms that can be used to describe this situation, including "overlooked," "ignored," "neglected," "abandoned," and "disregarded." These words convey a sense of something being left behind or forgotten, either intentionally or unintentionally. Other similar phrases that can be used include "missed the mark," "strayed from the path," and "deviated from the plan." Regardless of which words or phrases are used, they all share a common theme of losing track of something that was once considered important.