Yes, you are smart. People can be triggers. So can places, events, situations, sounds, tastes, thoughts, touch, animals, tv, colors, material, light or lack of light, intimacy, smells, objects, you name it. Memories get stored in the mind and body. Sometimes it takes something close to the "trauma" or the situation to trigger us emotionally. It may not make sense in the present but it's relationship to the past can help us become detectives and solve our mysteries. It sounds like you are becoming quite the expert sleuth yourself. Be kind and allow your process to take it's time. A respectful process is a healthy one. Good luck!
Hugs!
dazeofdolphins