transient or fleeting; existing for only a very short duration

这种虚名如朝生暮死，转瞬即逝，不值得去苦苦追求。

idiom · born in the morning and dying at dusk; having an extremely brief life cycle

蜉蝣虽然朝生暮死，却在有限的时间里完成了生命的延续。