You probably had food in your home as a child and parents who were willing to give it to you.
Many children go to school hungry every day because parents can't (or more commonly won't) provide food for them at home. Hence the breakfast at school and the afternoon snack. In my kids' school, over 50% of the students are free-lunch eligible. Teachers do everything they can do insure that kids get as much healthy food as they can during the school day, because they don't get it at home; this includes a relatively heavy "snack" at the end of the day to try to tide them over until the next morning, when they can get a breakfast at school. I'm in the process of trying to start a weekend backpack program to send those kids home with food on the weekends because a lot of their parents don't provide them with food all weekend. Can you imagine going from Friday at 5 pm until Monday morning with nothing to eat? That's what a lot of these kids experience because they're either alone (mom or dad leaves them unsupervised), don't have a responsible adult to get them food, or don't have any food in the home to get themselves.