Ok, so my experience with this drama was interesting; I watched the first 19 episodes which were quite good but I got annoyed with the OTT antics of the antagonists: the crazy, shrill mother in law, the psycho, hysterical 2nd female lead/love rival, the slimy, greedy and very many business rivals and finally the cowardly, pseudo-cool big brother. So at that point I decided to give it a rest, but I wasn't willing to drop it because I could see that there was something there, I just had to refresh myself and come back to it later ( the large episode count was also very off putting )
I took a break, watched Goblin and Marriage Not Dating ( I watched both within the space of a week!) and then I picked The Wife's Secret up again.

I started off watching on fast forward from episode 20 to episode 30, then gradually without even realising it I stopped fast forwarding and was fully engaged. I do admit that you have to suspend logic sometimes in this drama, the melodrama and illogical decision making of the characters was not realistic and was frustrating in a lot of instances.

However, this drama has a solid story, it explores family relationships juxtaposed with romantic relationships, it explores blood ties juxtaposed with ties that a person chooses themselves, it explores the relationship between parents and their children, mothers in law and daughers in law, it explores the dynamics that play out when a child discovers that they are adopted and most importantly it explores the meaning of true happiness, is it money? business success? or having family and people around you who love, accept and value you for who you are not what you have or can do for them?
This drama explored all these issues and answered them.

The drama has overall, one of if not the best character development I have seen in any drama, the character arc for most of the cast is very satisfying and logical; even those characters I disliked so much in the beginning are fully realised by the end of the drama, there is a strong sense of most characters coming full circle and applying their experience to improve themselves or to come to terms with issues that they struggled with in the beginning of the story.

I've read some reviews where the two leads are criticised for not having much chemistry; I fully agree that the OTP had very little on screen chemistry, but I think that's because it's not that kind of drama, although the love story is at the centre of the drama, the surrounding family circumstances are integral to the progression of this love story and vice versa. So overall I would say that this is a story about family, the family you are born to and the family you choose along your life journey.