Stoicism famously teaches that Virtue is the only real good, and failure of Virtue is the only real evil. All other things - all external things, that do not depend upon our choice - are classified as "indifferent." To some ancient Stoics, this was all there was to the scheme of the world - choosing to act in accordance with Virtue is Good, choosing to act contrary to Virtue is Evil, and external things - possessions, people, position, etc, - are all Indifferent.
The problem, of course, is that most people mistakenly value indifferents as if they were true Goods. So they seek social position, they seek money and possessions, they seek pleasures of food and drink and sex, etc. - all of which are (in and of themselves) Indifferent, since they lie beyond the sphere of moral choice. But is it not better to be in good health than poor health? Is it not better to have money than to lack money? And so some ancient Stoics took a more nuanced view of Indifferents, that they could be "preferred" or not. In other words, good health and wealth are not Good, and cannot be, but they are preferable in most circumstances to their opposites of illness and poverty.
Hence Donald Robertson writes in The Philosophy of Cognitive-Behavioural Therapy that "it is generally considered rational to prefer having external "goods," such as food, wealth, sex, social praise, etc., over pain and poverty, so long as these things do not have an adverse effect upon our mental health and well-being. The Stoic by no means claims that 'all pleasure is bad,' which would be the opposite of 'indifference' in any case. He simply does not see it as inherently important. The Stoic technical term sometimes translated as 'serenity' or 'indifference' (apatheia) actually means the absence of irrational or excessive passion (pathos) . . . Seneca suggested that it would be preferable to explicitly emphasize that the Stoic term apatheia refers to a mind which is 'invulnerable' or 'above all suffering', i.e., free from irrational or excessive passions (Seneca 2004, p. 48)."
"The Stoic can, therefore, take worldly things or leave them, but either way he does not get overly worked up about them. Wealth and fame, sensory pleasure or social praise, can only be either good or bad in a trivial sense, but genuine happiness is ultimately down to our attitude toward life, and the use we make of our intellect."