People are very fortunate if they came from loving and nurturing childhoods in which they were allowed to develop healthy self-esteem and had good role models. But those of us who didn’t need books and other resources to help us with our relationship issues.
It's quite clear that childhood events influence how we handle relationships (as well as other matters in life). Our minds store all of our childhood events in such a way that we live them out later. These “re-lived” events may look different than the experiences that inspired them, but they are essentially representations of those former experiences.
This likely happens because we are “wired” to repeat patterns as we go through life: We humans are creatures driven by habit rather than by instinct. And when we have patterns in our lives, especially ones that were formed in early childhood, by default those patterns will be the things that we repeat. Also, it's likely that subconsciously we will go about things in a way that we believe will be healing to us (even if those things that we go about are actually detrimental to our healing).
Unresolved conflict is something that we seek to heal from—that is a popular belief among psychologists. Subconsciously, we're seeking to do things such as heal from unresolved conflicts with our moms and dads and see our potential mate as our early caregiver. It's often the case that relationships must go through very difficult times if the people are to be aware of the things that happened to them in the past. When those things come to the surface, though, anchor, grief, and negative feelings can be addressed. And it's the case that romantic relationships will trigger the worst in us before they trigger the best in us.
I've been in love more than once in the past. And when I found myself struggling with my partner, then issues related to childhood struggles would surface. But at the time I wasn't conscious enough to identify what was going on or prepared to do the work that would be necessary to fix things.
I need to go off on a tangent briefly to mention something that I'm very convinced of: I believe that modern day psychology has advanced humanity’s understanding of itself, but I don't believe that psychology is the only way to go about solving mental and emotional problems. I know that there have always been people in remote places who didn't require things such as psychology, philosophy, and special treatments for mental illness to heal themselves from the emotional wounds of their childhoods. And I don't think psychology has come up with a universal solution of how to understand all of our mental and emotional problems and subsequently fix them (at least within a reasonable period of time).
Regarding my own discovery, I want to really dive into myself, understand my issues, and be involved in extensive emotional healing work. And I know that my romantic relationship will be an accelerator. Other things, such as solitude, consistent meditation, talking, and being of service to others will help tremendously as well.