迷失沧海那桑田
[mí shī cāng hăi nèi sāng tián]
Derived from ancient poetry 'Cang Hai Sang Tian,' which means the sea turns into mulberry fields; it metaphorically suggests a profound shift over time. 'Lost in Canghai (vast sea) then sangtian' represents a feeling of bewilderment due to drastic changes around one.