既有今日，何必当初

jì yǒu jīnrì, hébì dāngchū

[if there must be today, then why should there have been other days; if I had known it would come to this, Iwould have acted differently; if it has to be like this now, it's a pity it was even like that in the beginning] 既然有今日的如此结果, 何必在当初那么做。 用以感慨现今的不如意, 而深悔过去的错误

宝玉在身后面叹道: "既有今日, 何必当初。 "--《红楼梦》