No matter how much research experience we have, how many guidebooks we have read, and how many seminars we have attended, we all have gaps in our knowledge.
Those gaps can be because there are factual details we simply never learned about records, places, or events we think we know “everything” about either because we were never exposed to that information or when we were, for one reason or another, we ignored it.
There may be aspects of our ancestor’s social existence that we don’t “get” or understand because our own existence or experience is different. The dynamics of a large family may not quite be understood by someone whose immediate family was quite small–only children of only children have a different reference point for family interaction compared to someone who grows up in a family of eight siblings where each parent had that many siblings.
If you grew up in a family that was “close,” it can be difficult to imagine a family where close relatives lose contact forever because it’s somewhat common for people to permanently stop speaking to each other.
Genealogists can easily have gaps in their “book learning” about genealogy and in their understanding of the family dynamic in the family they are researching. It’s always advised to remember that.