In hindsight, a better campaign could have been designed to ultimately ensure the impressions of our ad.

事后看 当时应该设计一个更好的推广活动来确保广告曝光率

What looks obvious in hindsight was not at all obvious at the time.

事后一目了然的在当时根本看不清。

In hindsight (5 years later!)

事后(5年后！)

In hindsight that was a huge mistake.

日后才发现是一个巨大的错误。

In hindsight, it was unwise risk management.

事后看来，这是不明智的风险管理。

In hindsight, this turned out to be unnecessary.

事后证明，这项法案是没有必要的。