ELI5: Explain Like I'm 5

Hindsight bias

Hindsight bias is when you look back at a situation or event and think you knew what was going to happen all along, even though you didn't know before. It happens when we think we knew it all along, even though earlier we didn't know what was going to happen. It's like when you watch a movie and think you knew who the bad guy was all along even though you didn't know it was them until the end.