This is where problems start. There is nothing wrong with boys being “exposed” to girls as long as it doesn’t violate halachah. When we pretend that the opposite gender doesn’t exist, it causes problems when they are “exposed” down the road. Boys need to know that girls/women are out there, and that there’s nothing wrong with being around them as long as it’s done properly. By “being around them”, I mean things like having a bus driver, sitting next to a woman on a bus or train (which R’ Moshe Feinstein says clearly is allowed l’chatchilah), in the workplace, or in a grocery store.
I was in a store recently, and a frum woman asked me for help – there was an item on the top shelf that she couldn’t reach, and she asked me if I could get it down for her. I was in a different store recently in a more right-wing community, and I saw two girls shopping. They were actually climbing on the shelves trying to reach the top one. I asked them, “Would you like some help getting something from the top?” They just looked at me like I was crazy, and kept trying to reach things. They didn’t even say “No thank you”. This is what we get to when we think of stupid questions like the OP.