I tend to feel like I had a relatively happy childhood. My parents made mistakes like all parents do, and there were life events that happened that weren't fair, but overall I didn't have anything overly tragic happen in my early childhood.
I also have a pretty good memory and can recall specific events from the age 3 though adulthood. But, I noticed in the 4th grade that I simply didn't have any memories from the 2nd grade beyond just 2 or 3 things. That has always bothered me, and as I get older the more it bothers me. I've asked my mom, but she can't think of anything that would have caused me to block memories. I've just accepted now that maybe nothing memorable happened that year.