In my family, there were several topics that were not discussed - at least not with "the children". So I did no know that my uncle committed suicide by taking cyanide. (He was a jeweler and thus had access to cyanide which is used to purify gold.) I was able to obtain the death certificate at the state archives.
Nor did I know (until I recently asked my elderly aunt) that my other uncle divorced his wife (my father's sister) and remarried. I obtained more details on that one >from his will.
And in my husband's family there was a great-cousin who "worked in a saloon" in the western part of the US. A mutual cousin of my husband was reluctant to share any information about her. The important part is that she died young and may have suffered >from a chronic genetic disease which we know has affected one branch of the family for over 4 generations.
As genealogists we often uncover details which might otherwise remain hidden. Some of those details may prove to be highly significant.
