I love that saying! I used to use it all the time with my brother and sister. We'd laugh and laugh.
Now, however, I wonder how many of God's created don't use the one He's given them. If you are a follower of Christ, you have an obligation to use your brain, not just your emotion, which are wonderful, not just your experiences, which are vital to our growth, you must use your brain.
Here's what I mean. The Bible teaches us that we, through the Spirit, can have wisdom, insight, knowledge, understanding, discernment. These are all found in our intellect. However, these are wrapped up in the Spirit and many times fall outside the parameters of our own human knowledge. The point is that we need and should make the study of God's word, and outside sources, something we love, something we desire, and something we give priority to.
I'm not saying we should all go get a theology degree, but I do believe that we need to be able to answer to anyone why we have our hope. We also need to have the humility to say, "I don't know...but I'll find out."
The Bereans, in Acts, were commended for their study of the Scripture to see if what they were being told about Jesus was correct. Many times believers will take a Pastor's word or a teacher's word for it without having a clear Biblical understanding of a topic. Thousands follow false teachers and false prophets because of a lack of Biblical knowledge.
Biblical knowledge goes beyond knowing chapter and verse. God has provided many men and women who understand the original language of the Bible and have taken great pains to make sure we get those resources in hand. On top of that, there are many other resources that, though might need some explanation, are easy to use: concordances, study books, commentaries, web sites. Each of these will not only enhance your study of the Word, but enrich it!
Finding out the original words or the author's original intent, or even the connection between the ancient Jewish beliefs and our beliefs, is only found in taking time to study the works of those who have given their time and careers to offer us such great resources.
All in all, study of the Word is valuable, necessary and down right awesome!