The word 回忆 is formed by combining two characters that each contribute a conceptual layer to the idea of remembering. The first character, 回 (huí), means "to return" or "to circle back", providing the imagery of turning or going back in time or space. The second, 忆 (yì), carries the core meaning of "to remember" or "to recollect". Together, they create a compound where 回 acts metaphorically upon 忆, visually and conceptually depicting the act of memory as "a turning back to recollect" or "a mental returning", effectively capturing the process of the mind revisiting the past.