Forgetting about your infant in the backseat. Can this really happen to anyone?

I was listening to a commercial on the fm radio during a long drive this morning. It claimed “forgetting about your baby in the car can happen to anyone”. Really? Um, I’ve never forgotten when my children were with me. Never.

Is this a 21st century problem? Did this happen in the 60s? 70s?

How do parents forget their baby is in the car, then leave them to die in the heat?