Why do I avoid conflict?
You avoid conflict because some part of you learned, at some point and usually early, that voicing disagreement cost more than it was worth. Not in the abstract. In a specific memory your body still keeps, even if your mind has filed it away as old news.
What is actually happening
Your nervous system does not distinguish well between a raised voice in 2015 and a raised voice today. If disagreement in your house growing up meant someone got cold, or loud, or left the room for three days, your body logged that as data about what conflict does to relationships. Now when a coworker pushes back on your idea in a meeting, or your partner brings up something you did wrong, your chest tightens before you have consciously decided anything. That tightness is not overreaction. It is an old alarm doing exactly what it was built to do, just firing on a target that is not the same size as the original threat. The avoidance you feel as a personality trait is really a prediction your body is making faster than your thinking can catch up to.
Why it makes sense
If you grew up where conflict was unpredictable or disproportionate, silence was a genuinely good strategy. A kid who stayed quiet during a parent's bad mood got through the night better than a kid who pushed back. That is not passivity, that is skill. You read the room accurately and adjusted your behavior to survive it, which is a form of intelligence, not a deficiency. The problem is not that you learned this. The problem is that the skill generalized past its original context, so now you are using a strategy built for an unsafe adult against a partner who would actually welcome you saying what you think. The instinct was correct once. It is just old information running the show in a new environment.
What actually helps
Stop trying to become a person who loves conflict, because you probably never will and do not need to. Instead, practice tolerating the physical sensation of disagreement in low-stakes moments, telling a barista they got your order wrong, correcting a friend about a fact, saying "I actually don't want to" about a small plan. Each time you do this and nothing catastrophic happens, you are giving your nervous system new evidence to work with. Separate the content of what you need to say from the delivery, write down the actual sentence beforehand so you are not composing it live under stress. And notice the difference between conflict that clarifies a relationship and conflict that was never going to go anywhere, because you do not owe every disagreement your energy, only the ones tied to something you actually care about.
When this runs your life, it usually traces to one underlying pattern. For this, it is most often the Ghost rhythm, the thing under the behavior.