流连忘返 is formed by combining the two-character phrase 流连, meaning "to linger" or "to be reluctant to leave", with the phrase 忘返, meaning "to forget to return". The character 流 conveys wandering or flowing, 连 implies continuity, together suggesting prolonged attachment. 忘 directly means forget, and 返 means return, so 忘返 expresses neglecting to go back. Thus, the four-character compound literally means "lingering and forgetting to return", depicting a state of deep captivation.