The academic narrative of publish or perish, the seemingly constant inflow of rejections (papers, grants, fellowships) makes our lives challenging and fills our hearts with anxiety, maybe even rage. We might have trouble sleeping, lose pleasure in food, and turn inward. And think: this is the biggest failure of our lives.
A way to fight these negative thoughts is to harden up and grind further. But I need to re-issue the warning from British mathematician and philosopher Bertrand Russell's book, The Conquest of Happiness:
One of the symptoms of an approaching nervous breakdown is the belief that one’s work is terribly important.
However, introspection can materialize a soothing and reassuring alternative. Namely, to realize that however important and life-changing these events seemed to be, this is not the end of the world.
As the writer George Eliot (a.k.a. Mary Ann Evans) came to the same realization after a youth full of disappointments (I recommend reading not just the corresponding chapter but the whole of The Road to Character, emphasis mine)
When we are young we think our troubles a mighty business—that the world is spread out expressly as a stage for the particular drama of our lives and that we have a right to rant and foam at the mouth if we are crossed. I have done enough of that on my time. But we begin at last to understand that these things are important only to one's own consciousness, which is but as a globule of dew on a rose-loaf that at midday there will be no trace of. This is no high flown sentimentally, but a simple reflection which I find useful to me every day. Gordon S. Haight's George Eliot biography, p. 144
If we treat those events as life-or-death, they will become such in our minds. Changing how we think about them internally does not change the external outcome, so fussing can only make our life more miserable.
Who wants to make their life more miserable?
Though no one would answer in the affirmative, we still become sinners in what Seneca expressed in his thirteenth letter, On Groundless Fears, as
There are more things … likely to frighten us than there are to crush us; we suffer more often in imagination than in reality.
Rumination is not a friend but a foe; however, analyzing events in hindsight is still instructive. We can learn from our failures, if nothing else, then to tame our reactions the next time―lo and behold, not all failures are good, as I wrote about it previously. Maybe the reviewer did not understand your point, but maybe it was not clearly written.
Self-reflection will not fix the past, but the past is not there to fix. It is to learn from such that we can improve ourselves.
P.S.: you might also enjoy the conversation between neuroscientist Andrew Huberman and ex-Navy SEAL Jocko Willink on The Huberman podcast, where they extensively discuss the same topic