蝴蝶虽美终究飞不过沧海
[hú dié suī mĕi zhōng jiū fēi bù guò cāng hăi]
Inspired by the idiom butterfly cannot cross the sea however beautiful it may be, it metaphorically portrays fleeting beauty versus long-enduring time; highlighting the difficulty in attaining certain desires even though they are desirable, emphasizing transient and ephemeral nature over lasting stability.