It's easy to have twenty-twenty hindsight.
twenty-twenty hindsight
idiomA perfect understanding of events only after they have happened.
Origin
disputed originFrom the term 20/20 which is used in visual testing to refer to normal visual acuity.
With twenty-twenty hindsight, I see that quitting my job was a mistake.
The historian, armed with twenty-twenty hindsight, judged the general's decision harshly, forgetting the chaos and uncertainty of that winter morning.