Also, on the subject of forgetting babies, here's a story of my sister's family with a happy ending as it only lasted about 3 minutes.
They were going on vacation and drove their car to the airport. They have two kids, an almost 3-year-old girl and a 6-month-old boy at the time. They were parking in an off-site lot with shuttle stops, so my brother-in-law dropped off my sister, the 3-year-old girl, and the luggage. Then he went a few aisles away to park.
When he was approaching the shuttle stop, my sister just stared at him and asked: "Where's Leo?"
It was probably 3 minutes he was left in the car, and it was cool outside, so no harm done. My brother-in-law ran back and retrieved him, no harm done. Still, an example in our own family of forgetting about a kid.
P.S. My friend at work has a 2-year-old and is pregnant with twins. Her mind is frazzled, and she is terrified of leaving her daughter in the car like that. She's started taking a timestamped picture of her daughter's empty car seat when she parks at work, and there's a number of us who ask her (at her request) to show us the picture when we first see her. Before the photo idea we would ask, and she would believe she dropped the kid off but not be 100% certain and would go back out to her car to check, every time.