You are not a parent, obviously.
Hmmm...that would be news to my three small children. My children mean the absolute world to me. The reason I have such sympathy is because I know, first-hand, how easy it really is to do something like this. It is so very easy to just assume that each such instance involves a reckless parent who prefers a drink at a bar to safety and well being of their child.
In my very personal case my little girl was a little under two years old. My family and I were heading into church with my frail father-in-law. I dropped my wife and her father off at the church door step and went to park the car with my three kids. It had been our custom at the time that my wife took our baby daughter and I took the boys. In this instance my small boys bolted from the car and I feared for their safety in the parking lot. My daughter dozed quietly, and out of view, in the back seat while I dashed to grab the boys. After church service was over I went to the nursery to pick up my daughter. They told me she had not come that morning. It hit me like a load of bricks at my realization and I ran to our van with tears filling my eyes. As I got to the van I opened the door not knowing what to expect but preparing myself. There was my daughter with eyes red from obvious crying with a look on her face that I swear I will never, ever forget to the day I die.
Fortunately for me it was a fall day and about fifty-five degrees outside and my daughter was no worse for the wear, unlike her father at the time. We made a point of never saying anything about it to my daughter because we did not want to reinforce a bad memory. At six and a half years old she has no recollection because we have now asked her if she remembered. We are thankful.
It is easy to hurl bricks simply because it just never happen to you. For me, I see someone kneeling in the sand, writing, and asking for him who is without sin to cast the first stone.