[似曾相识 / 似曾相識, sì céng xiāng shíㄙˋ ㄘㄥˊ ㄒㄧㄤ ㄕˊ] déjà vu (the experience of seeing exactly the same situation a second time); seemingly familiar; apparently already acquainted#25060
[曾经沧海 / 曾經滄海, céng jīng cāng hǎiㄘㄥˊ ㄐㄧㄥ ㄘㄤ ㄏㄞˇ] lit. once experienced the vast ocean(成语 saw); fig. widely experienced in the vicissitudes of life; cf. to have known the world#48688