Hindsight is (always) 20/20 American proverb sentence
The word "Hindsight" means understanding after something has happened. 20/20 is a term in ophthalmology to mean good vision.
The phrase implies that looking back on what happened is easy for someone to understand.
Hindsight is always 20/20. I should have listened to your advice.
We have realized his decision brought the company many problems, but hindsight's 20/20.
To fall suddenly and heavily to the ground
The biggest building was caved in last night due to the historic storm ever.