Sometimes, there is no "understanding" human nature - the fields of psychology and psychiatry are still in their infancy. We just don't know what makes human beings tick, though there are some pretty good indications of how and why. Understanding Self (that Life's Spark that makes us each unique) is much more important than trying to figure out why people respond to us positively or negatively. When we begin to understand Self, we begin to relax a bit about what other people might be thinking about us and begin to accept humanity as it is, faults, triumphs, and everything in between.
Finding a partner, as I'm sure you've been experiencing, is far more than just a superficial thing. Being comfortable with the Self will also allow us to be more comfortable with others, thus, peeling away the layers of superficiality and finding more of the core of that person. Sometimes, it's a delightful surprise. Other times, it isn't delightful, at all. Those things we learn to take in stride. And, "acceptance" does NOT mean "excusing" the bad choices/behaviors of other people. Sure, we're all flawed, but that doesn't excuse actions that are deliberately harmful with malice as the guiding hand. "Acceptance" is the ability to call a Spade a Spade without any gleeful undercurrent of "I told you so," or, "Take THAT!" We call 'em as we see 'em with objectivity and, if it's negative, we can comfortably walk away without harboring hatred, anger, resentment, and the need to "get even" with someone because we mistakenly believe that it will soothe our bruised egos.
There are so many, many books and articles written on developing empathy that it might just be better to Google, "empathy!" But, allowing your Self to feel FOR others is another good way to learn about your Self.
There is much to learn in this Lifetime and we will never stop learning unless we choose to. Even in the twilight of our years, there are still new things to learn about our Selves, others, and Life, in general. Keep taking those positive steps and allow for error, from time to time. We are all human, we all make mistakes, and we all take missteps. It's whether we choose to learn from our experiences or not that determines how deep the potholes in our Life's Path are going to be in the future. If we keep making the same negative choices, over and over and over, we have only our Selves to blame for individual discomfort.
Your original message to this thread is probably the most positive that I've ever read from you - BRAVO! Good for you, Rygar! I've been keeping you in my thoughts and prayers for a long while, now! My best wishes to you!