忘不掉的回忆c丢不起的曾经c
[wàng bù diào de huí yì c diū bù qĭ de céng jīng c]
This username expresses the bittersweet nature of memories that one cannot let go, where 'c' might be an additional symbol for emphasis or personal significance. It conveys the feeling of being unable to forget important past events or emotions, even when they are painful.