retrospect

In retrospect, I should have taken the job offer when it was first presented.

(Chinese) 回想起来，我当初在工作邀请第一次提出时就该接受它的。

The errors in the plan are very obvious in retrospect, but they weren't at the time.

(Chinese) 回过头来看，计划中的错误非常明显，但在当时并非如此。