Oh, by the way, to underscore the concept that this is about your body and not your shortcomings (regardless of whether your body was damaged by childhood trauma or dietary deficiencies or exposure to certain drugs or whatever) - I will briefly share my experience.
In 2008 I was pretty sick. I won't bore you with the details, but I was in very bad shape. Not cancer or anything, but I just did myself in, in a serious way that affected my daily life bigtime (couldn't function). Saw doctors, got tests, etc. I hit upon a description of adrenal fatigue, and while I don't think that was the only thing going on I think it was a big part of it. But one of my symptoms during this time was - you guessed it, I was extremely sensitive to things. I had several incidents where I was literally traumatized by hearing of things. I couldn't sleep, I couldn't get those images out of my head. I cried a lot. Separately, if I saw a movie I would be holding back tears at scenes that were emotional, even stuff I would have considered corny before - the non-traumatic birth of a child, a romantic embrace, a peaceful death (like the end scene in The Notebook).
All I'm trying to say is, I'm not even like that normally. And it happened to me. It could happen to anyone. I'm not a stronger person than you. I just have apparently somewhat healed an imbalance I had. I don't think I'm 100% healed yet, and frankly I think I will forever be more sensitive to things now that I'm a mother, compared to my pre-mother days (and I think this is good and natural), but I can now get through a corny movie without clutching kleenex again