Why are the SO lazy?

I was the closing manager tonight and I came to the realization that 15 year old boys ARE LAZY!!!!!! When a normal person is told to sweep something, the do. Not half of it, not walk around and think about doing sweeping. But normal people really doing it!!!! Why is this so hard to get through little boys heads? Giving a demonstraion didn't even work? Guys, have a chat with your younger selves, they are making you look really DUMB!