From my experience this is very common, and that's with everyone. I have both a grandma and aunt that have had that experience. My aunt ate at a Mexican restaurant once and got food poisoning. She has never went back. I've been tons of times but never got food poisoning. My grandma got food poisoning from pizza one time, and that was like 30 years ago and not only will she never eat at that pizza place again she has never even touched any pizza again.

I think it's kind of human nature. We remember we felt that one time and we don't want to feel it again. I've only had food poisoning once and it was from Olive Garden. I've went back though. I did feel sick from stew one time though (I was also drinking) and I haven't ate stew since.