My take on it is trusting others really comes down to a question of whether I trust myself. People are unpredictable. As trustworthy as they want to be, they are human and dealing with their own issues and aren't likely to behave as I'd like them to 100% of the time. But, if I can trust myself to be okay even when others change the game plan, I can relax. I am hypervigilant because I know I haven't gotten to that place of equanimity and that a small eddy can feel like a tidal wave. It's not so much about others, it's about me. That's as far as I've gotten, anyway.