Self CheckOut

So, what I am about to talk about annoys the crap out of me. Self Checkout lines at grocery stores are suppose to be quick and easy. You don't bring up 20 items to the self checkout lines. In fact, I believe there is a sign that states 10 items or less. And why on earth would you want to bring up 20 items to self checkout? And alsok don't you think if you plan on using the self checkout stand that you should actually have some idea how to use it? I mean, isn't that the most logical thing? I stand there and watch one person after another just continue to look lost and confused with the what could be one of the most easiest and convenient ineventions. It drives me crazy!!!