What past was his father trying to change???

Rating: Null/10 (20 September 2004)

I only saw the DC, and I do believe that the movie is straight forward and plays itself out on screen.
I did catch the "3 stillborns". Implying a cycle of stillborn suicides.
My question is.....When his father was in his early 20's, I assume some time around the birth of Evan, what in his past was he trying to change??
He used a camera to document his past like Evan used a notebook, but the pictures were of random offcentered photos of nothing.
I am wondering if I missed something or is it just a topic that was left up to the imagination of viewer.
Man...10 lines! OK. Well, how did Evan not kick the crap out that little S**T? He was like a foot shorter and way lighter! And why did the hit on Hayley's face change, first was to side of head, the second to the cheek, leaving that nasty scar?