I have known the 23rd Psalm since I was a child. A friend was given a Bible for perfect attendance in her Sunday School, and she shared that Bible with me. Together we learned the words of the psalm, and ever since it has comforted me on many occasions.
Psalm 23 is one of the shorter psalms, with only six verses, but it depicts an intimate relationship with a tender God and assures us of His loving presence.
I had occasion to experience proof of this one night when our youngest child was a baby. He was suffering with a cold and having difficulty breathing easily. I took him in my arms and began praying with the psalm because it was the first Bible text that came to thought. I was grateful that I knew it by heart. Initially, I repeated it over and over.