Don't get the wrong idea. W Philip Keller's book on A Shepard's look at Psalm 23 is an excellent book. Here is an attempt to bring out how a layman understood this Psalm. Psalm 23 is likely written by David before he became king. The writing brought out strong sentiments of him as a shepherd and when the enemy's presence was still felt. David was a good shepherd, he fought lions and bears for his flocks. 1 Samuel 17. Being a good shepherd, David understood that a good shepherd will do all for the flock and not harm the flock. A good shepherd leads the flock to the best place for food and water. The good shepherd walks with the flock through hills and valleys. The staff of a shepherd is for protecting and guiding the flock. You can see hence that God is the good shepherd always provide and protect. The second part of the Psalm speaks of God generosity and kindness. God prepares feasts/meals during times of anxiety. Anoint with oil speaks forth honor and an overflowed cup annotate that of abundance. The journey with God always results in honor and blessings.

May we trust God like David in all circumstances.