I find I've written before about my mother's moods, about how she treated me badly when I was in high school because she was trying to drive me out of the house (at her boyfriend's instigation). Coming home was making me get stressed out because I was being attacked all the time for I knew not what. It all made so much more sense when I realized that he'd told her I was the one standing between them. I only found this out after he'd broken up with her ... once she'd managed to get me out of the house and discovered it wasn't really me keeping them apart, it was his wife and baby.
And then there's the child abuser I lived with for most of my youth, from 6 to 15 or so. I always had to keep an ear to the ground to avoid being caught in a bad scene with him - hard to detail too much here (as I'm planning on leaving this post public), but suffice to say I had to be very aware of the clues of when it was safe for me and when it wasn't and I needed to go straight to my room and lock the door.
Conclusion: paying attention to people is a survival skill. And while it's nice to assume the best, it's no way to protect yourself from a world which is actually full of a lot of nasty people. I don't expect the worst of people, even though I do know more about the bad things they're capable of than I'd like to. I do believe that life is full of disappointments, though, and it's better to shield yourself with low expectations and the hope that you'll be surprised with something nice, someday. (Like not getting that Tripadelic job? If I'd got my expectations high, I would have been crying when they told me no.) And, well, it's good to be the person who does nice things for other people when you can, because God knows there's little enough of that going around.
And also, today has been missing my grandma day, so I've changed my user picture to one of her. I always knew that she really loved me, even though I made her really mad sometimes.