Hindsight Fantasy
The depressing act of fantasizing about what you would have done differently if you knew what you know now.
"I would've stopped her from going out for a jog that day if I knew she'd get hit by a jumbo jet, she'd still be alive and so would the passengers on flight 123 and I would become a total hero and not have to keep working this stupid job"
"That's a nice hindsight fantasy, but keep on scrubbin' - those dishes ain't gonna clean themselves."
"That's a nice hindsight fantasy, but keep on scrubbin' - those dishes ain't gonna clean themselves."