Well, being married myself, I too have my own personal study time, but I also share, instruct, discuss and hold accountable my wife to her own personal study. We may not always pull apart a passage the way I do in my own study, but we have a time of devotion each day after dinner.
This is not only something we do to strengthen each other and our marriage, but also an example for our daughter (and other children yet to come).
I know that by sharing with my wife, she helps keep me in check. How would the husband know the condition of his wife if they never discuss or study together?
God's word is something that we, as Christians, should rejoice in! We should never tire of sharing it with others, especially our spouses! After a life time of studying it, we will never fully grasp the complexities of God! When I said, "I don't understand why a spouse would want to keep something from the other one" I was not referring to secrets, rather I was referring to the word of God!
In regards to his personal struggles, I can tell you from my own experience, I don't hide anything from my wife. Even if I look at another woman with a lustful eye, I tell her. 1.) I have sinned against her, and scripture says to seek after the one you have sinned against before you seek God and 2.) she can't help me if she doesn't know I'm struggling. If she knows what I struggle with, she can pray for me and hold me accountable to those things. For example, if I struggle with pornography, then she will know not leave me home alone. If I struggle with drinking, she will hold me accountable to refraining from going to a bar or purchasing alcohol.