the more we learn, the less we know

If someone says the more we learn, the less we know, they mean to say that the more we learn, the more we tend to understand how much we have yet to learn. Rather than being a literal phrase where you learn new things and then forget new things, the phrase means quite the opposite. If you begin becoming wiser to the way the world works, and understand more things, you will then be able to understand how much you still have to learn.