Hindsight is 20/20

Meaning that everything becomes clear when you look back at it after it has happened.

What does “Hindsight is 20 20” mean?

It means that your understanding of events is very clear, like perfect eyesight, after events have happened. It implies that it is easy to say what **should** have been done, or what **should** have been different, when it has already happened and it is already too late.