Probably, the best way to start here is to share a quote. There is a non-English quote that says: "Part of wisdom is not saying everything that you know".
What that quote is saying is that, there are always more to what other people are saying. There are things that we have within us that words fail to express sometimes. Those untouched territories of oneself sometimes feels better to be kept a secret. A true secret, something that has not been shared with anyone or will never be shared.
I wonder how was Nikos Kazantzakis was thinking at the time when he said: "I am afraid to die and there are so many untold stories within me". Or to even think of his emotions at the time of writing that quote.
So, what we can say is that it is true that there secrets. Sometimes we hear people say that they are a clean slate. That they are very transparent with everyone and they have nothing to hide.
Nothing to hide? Really? Am I wrong here when I think that it is madness to have say everything to everyone?
I could be wrong here. But, is it wise to say everything as your eyes see it to everyone. Sometimes, our words make a better reality to another being. Sometimes, we sense that it is the best thing to do is to be compassionate.
I will just end this with saying that every person has their own mystery box from within.