Concordances and Bible Knowledge

Yesterday I challenged an adult sunday school class to find verses that support the list of godly heart attributes we had come up with. So they began looking for verses that talked about the heart being truthful, gentle, courageous, etc.

Everyone used the concordance in the back of their Bible.

What does it say about the depth of our Bible knowledge that we are completely dependent on a concordance to find Bible passages? (Let me be clear, I use my concordance a lot, so I'm not talking down to anyone!) How much Biblical knowledge have we hidden in our heart?