The happiness that may emerge from taking a second look is central to Proust's therapeutic conception. It reveals the extent to which our dissatisfactions may be the result of failing to look properly at our lives rather than the result of anything inherently deficient about them.
The situation that women were in, at the time, was something that Dumas doesn't really go into, but it's a great subject to look at. It's a great genre because you can do a lot. Sometimes in thrillers, you can really explore things, and it's the same in this genre.
They're classic themes, which is why I think it's such a great story to look at again. The concept of being loyal to your friends, to the point where you'd even die for them, is a great subject.
If you must look back, do so forgivingly. If you will look forward, do so prayerfully. But the wisest course would be to be present in the present gratefully.