I believe the author is trying to convey that with the passing of time we are able to notice all the subtle things that come to define a situation or period of time which go almost unnoticed during the time or situation in question.
My grammar is most likely incorrect, but I feel like I might be able to help you understand. This next part should help convey the "feel" of the part you asked about.
Think about something that happened 10 or 20 years ago. If you are still a teen or younger, think back to when you were a little kid or imagine the way the world looked when you were born. I'm guessing that you get a mental picture of how things looked back then. What was popular, who the most famous people were, the songs that were on the radio at the time, the fashion trends, even certain colors can stick out when we look back at something. For example, the 1920's, 1960's, 1980's and 1990's all seem to feel different, at least in my experience.
Now, can you define how "today" will appear ten years from now? I know I didn't think the late 1990's looked anything other than "normal" or "right" when I was living them. Looking back now, I'm able to picture an era of grunge music like The Foo Fighters and Pearl Jam, rap becoming mainstream, young men with skater type haircuts, women with dark lip liner, new stories with Monica Lewinsky, 2pac & Notorious BIG, OJ Simpson and abundant jobs with new buildings popping up everywhere. I also think of the colors maroon and hunter green, things with sunflowers on them, Drew Barrymore and MTV.
Do you see how it's not until we are separated from an event or collection of events that we are truly able to see and define all the indirect things that influence or make up the big picture?
Imagine him speaking of "history" as if it were a person to which he gives the human characteristic of stubbornness.
Now try reading the sentence again, but When you read the part "stubborn" think of it referring to how long it can take before you are really able to "feel" an era or period in time. The "nuances" are the little things you pick up on in order to get that "feel".