Understanding that I was not responsible for editorial decisions, and that submitting of one's work was similar to applying for a job, helped me to deal with editorial rejection. Obviously, there are entire websites of people who will probably never understand these truths. It was a question of ownership. I own what I write and put my name to. Editors own their jobs, and the publications they put their names to. It's nothing personal. It's clearly professional to engage in realistic efforts to work toward sending appropriate work to the appropriate editor.
What I just wrote mostly applies to short fiction, which is mostly what I had written until the past two years (despite 3 previous novels). But when one is engaged in the practice of writing novels, it's different again from what I describe. We have the freedom to choose to write about any story we like. The reasons why we choose what we write are often simply described as "the story you believe in," or, "the story you have to write."
It never hurts to ask, "Why?" Why is this that story? Why should others want to read it, buy it, be interested in it?
In the same manner, I was able to understand and deal professionally with situations that many find unpleasant and sometimes impossible in the working world and in the classroom: firing someone, or failing someone.
Normal men seldom have the difficulties in these situations that women often encounter. They don't worry if the person who was fired won't like them. They don't fret about whether or not the student who was failed will try to retaliate, or make some type of complaint.
Little by little, step by step, I've been faced by situations where I've considered what somebody else would do in relation to what I would do. Now, it's wise to consider the impact of one's actions at all times. But by the same token, there are some situations where the necessary action must be taken, and the other individual's actions, reactions, or -- any thing they possibly could or would do -- do not matter. At all. Great managers and leaders know this. And now, I know it too. In all respects, and personally. I can and will apply the principle to my writing, to my personal life, and to my professional life. It only took 45 years to sink in. An amazing thing.