I came across an article on indifference written by a popularizer of Stoicism. This well-known author has done a service in terms of getting people to valuable historical works. I look at it sort of as a good introduction, a starting point from which one grows beyond.
That's an interesting point. Growing beyond. The student becoming the teacher. We can observe many writers/teachers who, having found a niche and little reason to experience further pains of learning, get stuck at that level.
In the article, the author says it's "not about apathy or even a lack of expectation. It’s simply the quiet strength of not needing a preference, because you’re that strong." Here the author misses a key facet of indifference. It is indeed very much about apathy - selective apathy - as well as managing (or reducing) expectations. "Quiet strength" isn't all that descriptive and implies some sort of emotional reductionism, which would logically lead to negating all preference. But it's entirely based on a bad premise.
Do not get rid of emotions or preferences. Rather, be indifferent about that which is out of your control. Understand that one of the greatest causes of misery is misplaced expectations. Expect you will not know how things will turn out. Expect people to act in odd ways. Expect conflict. Expect change. Expect ups and downs. Expect volatility.