既有今日,何必当初

词典解释

[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》