I learned a lot of new things, but the one thing that really stood out were the shoes. I never would have guessed the strings on our shoes were a simple machine. Think by not putting on our shoes or socks in the morning people would have smelly feet. So let me put it this way if we did not have this simple machine we would not have shoes or socks, and people would have really smelly feet at the end of the day. I think this is a very important simple machine, don't you?