I can't believe I forgot to post this!
Just last week I was in the Kmart parking lot putting my kids in the car when a car pulled in next to me with a sleeping baby in the back. The mom got out, looked at the baby and preceded to walk off. I looked at her and said, "You aren't seriously going to leave your baby in the car are you?". I think I took her by surprise. She said No, I'm just getting a cart (the other side of my truck). I felt kinda dumb but then I was like what if I hadn't said something. I did apologize to her and explained that people do some dumb stuff and she completely understood and thanked me for caring enough to say something.
2 days ago