Deuteronomy 6:6 (NKJV)
There is an old saying that states "A place for everything and everything in its place". The meaning behind this phrase is that to keep things organized there should be a place for everything and when that thing is not in use it can be stored in its proper place so that it can be easily found when it needs to be used the next time. For example, if you had a regular place to put your car keys it would then be easy to find them when you needed them. If you did not have those keys in a place where you can easily find them again, then you may have trouble locating them when you need to use them.
Deuteronomy 6 shows us the proper place to keep God's Word, in our heart. It does not say to keep God's Word on a shelf or just in our notes. We need to have God's Word in our heart to help guide us in our life and so that it is ready for use in our life as we need it. In Psalm 119:11, the Psalmist said that they kept God's Word in their heart so that they would not sin, Proverbs 37:31 talks about the righteous having God's law in their heart and the result being that their steps did not slide, and Proverbs 4:20-21 says that we need to keep God's law in our heart because it is life to us.
If we don't keep the Word in our heart, but only have it somewhere on a shelf or don't even know it, we will not only miss out on all the benefits of God's Word in our life, but we can find ourselves in some difficulty as we will not be able to use it as we should in our time of need. Having God's Word in our heart is a result of having a regular time of reading and studying the Bible as well as acting on the Word, this is how we make it a part of our life and get it into our heart. We all need to be sure we are taking the time necessary to get God's Word into our heart, that is the right place to keep it.