I hear this phrase a lot, usually accompanied by some hurry-up gestures: “We are where we are.” Heck, I might even use it myself. We've all been stuck in those one-sided conversations that seem to be more about blaming other people for what went less than well, rather than figuring out what to do next.
And yet... Often times it's necessary to review past actions and learn lessons. If we don't analyse the decision processes that led to poor performance or a bad outcome, then we're likely to make the same kinds of mistakes again. Sometimes it's worth looking back so you can move forward with confidence.