A call from an old friend

I've only had one major relationship before my current one. And I use the word relationship loosely. We were involved with each other for three years before I broke it off, due to the insanity which ensued in me from the previous years. The weird thing is that lately I have been having dreams (nightmares?) about what happened in the past with him and I don't know why. It seems like they've been haunting me for a while but at the same time giving me a sense of clarity. I've always had trouble with people's past and never knew why. Today I got a call from my old friend (again I use the term friend loosely) and I didn't know what to say. I didn't know whether or not to be angry, happy, or indifferent. I kind of answered with a weirded out voice because I thought we were done with whatever we were involved with. It turns out I was the only one who thought that. We basically talked about family and friends and eventually, relationships. I told him the truth, that I was seriously involved with someone. He wanted to do lunch and I kindly declined. When I hung up, I stared at the phone for five minutes. You can say I was nonetheless angry with myself for having issues with people's past, because after I hung up, I realized that what is in peoples' past is history and I shouldn't let it affect how I feel about the people that are in my life right now. And after all, that's all that matters, right?