See, the example you used was the grocery store in your original post. Not at your own home. I still would do whatever I had planned and if said neighbor tried to suck me in to a convo, I would firmly but politely tell them I was quite busy and needed to just get this done.
I don’t live my life paranoid, but I also don’t have this crazy family intent on ruining my life. That’s not paranoid to me, that’s assuring that they can never again do to me what they did 6 years ago.