Signs

I have never been in a relationship that I just didn't know the person I was involved with. My mind is reeling right now. I keep asking myself what the signs were that I could have seen. Why would a person I loved just go off the deep end so completely. What will I do different in the future? What could I have done differently? How can I be sure my next friend or lover isn't completely nuts? I guess there is no way to screen out the secretly seething angry person. No way to back away slowly when somebody doesn't show you their true self. It truly does break my heart to look back knowing I gave them a good chunk of it. What can ya do? Just get busy living I guess. Moving on.