What, then, do I mean to say by all this? It is this: I do not consider a man poor if he regards as enough whatever little remains to him.
Seneca has been using financial metaphors of gain and loss, applying them both to the concept of moral progress or loss and the gaining of or losing of (or wasting of) time. In the most recent post, he had declared that he has been reduced to poverty through no fault of his own; that is, he, as an old man, was being impoverished in terms of an elderly person's diminishing years.
But this was not a lament or complaint. The principle theme throughout this epistle (and a reoccurring theme in much of Seneca's other writings) has been the correct use of time and the notion that no life is too short if properly used. Just as a man is only as poor as he considers himself to be, no amount of time is too little for a man if it is enough for him.
And how is it enough? Because it is time used well. No man, not even if he has lived 120 years, can die contentedly if those years have been squandered in Vice. But Virtue makes a happy and contented man out of even the shortest life.
We need not pity the virtuous man who dies young, unexpectedly, or even unjustly; but we must pity the vicious man who lives a long life. As Seneca famously writes elsewhere, "It is not how long you live that matters, but how nobly." The poverty which is truly undesirable is not the lack of wealth or the dearth of years, but the poverty of Virtue. Where there is Virtue, there is no poverty and life is always complete.