I forgot my baby?!?!?!?

What kind of person “forgets” about their baby and leaves it in a parked car? I don’t have any kids (yet), but I have been in several relationships that included children. I can’t imagine being that absent-minded. The shocking part is not that this happened, but that it’s common enough to warrant new safety equipment in vehicles. Since that story similar incidents have happened in April, May & June. I’d like to enlighten everyone with an answer to this riddle, but I’m still dizzy from bangin’ my head against the wall.

UPDATE 2003 - Here is an updated link on this phenomenon and proposed solutions.