I understand more than the aged, because I have observed Your precepts.
Psalm 119:100

The psalmist continues to explain the benefits of responding appropriately to God’s word. He has already explained how God’s word has given him wisdom to deal with his enemies, and how meditating on God’s word makes him wiser than even his teachers who do not highly esteem God’s word.

In this verse, the psalmist reminds us that conforming our lives to what we learn from the commandments gives us understanding that even exceeds that of the aged.

The fear of the Lord is the beginning of wisdom; a good understanding have all those who do His commandments; His praise endures forever.
Psalm 111:10

Keep in mind that many people have a knowledge of God’s word, but that does not mean that they observe God’s word. Calling Jesus “Lord” does not mean anything if you do not submit to Him as Lord.

“Many will say to Me on that day, ‘Lord, Lord, did we not prophesy in Your name, and in Your name cast out demons, and in Your name perform many miracles?’ And then I will declare to them, ‘I never knew you; depart from Me, you who practice lawlessness.’ Therefore everyone who hears these words of Mine and acts on them, may be compared to a wise man who built his house on the rock. And the rain fell, and the floods came, and the winds blew and slammed against that house; and yet it did not fall, for it had been founded on the rock. Everyone who hears these words of Mine and does not act on them, will be like a foolish man who built his house on the sand. The rain fell, and the floods came, and the winds blew and slammed against that house; and it fell—and great was its fall.”
Matthew 7:22–27