I remember my first experience working with someone with trauma. She was a middle-aged woman with back pain who was quite rigid and despite us just meeting had mentioned a few negative-sounding comments about her husband. I didn't think much of it as a new clinician but some bells went off when I went to palpate her abdomen and she got very defensive despite giving me permission to do so. I felt completely unprepared to help her deal with this at the time.
Subsequent patients came and went and they had the same vibe of behaving in a self-preserving way, some more aggressive than others. Many, when they did volunteer information, described difficult childhoods. Unsurprisingly, they now presented to me with physical pain, tension, and chronic stress.