Famous among the playlists of men is the song, "Satisfaction." In it the Rolling Stones just can't seem to find or get any satisfaction. God's first song in His playlist speaks of why they couldn't - and how we can. It all has to do with what your delight is.
The blessed and happy man delights in the Law of the Lord, and considers it day and night. Many sing of their beloved, "I just can't get you outta my head." But for David, what he couldn't get outta his head was God's Word. He couldn't get it out - because he was making a decided choice to put it in the first place.
Consider this - David said that happy people don't focus on the counsel of those who walk in ungodly ways. He said the happy man doesn't frequent the path sinners are on either - and he definitely doesn't sit around with those who mock and spurn God and His ways. Doing these things will make sure you don't have any footing in the judgment. You become like chaff - (Dust in the Wind, if you will) and are blown away by even the slightest of even Summer Breezes that might blow across your mind.
It may help us to remember that the blessed or happy person is one who is living for Heaven's smile and approval - and not for selfish or self-centered things. Seeking the smile of God though, requires filling your head with the words and thoughts of God. We do that by delighting in His Word. Delighting here means having it in our thoughts. The phrase becomes, "I just can't get your Word outta my head." To be perfectly honest - we don't want it out either.
Love letters and messages from one's beloved are another item that fills our songs. David knew that God's Word - even His Law - was God's love letter to His people. Therefore to have it fill his mind was his delight. David knew that even with God's commands God was not seeking to limit his joy, but maximize it. He sings that the Lord loves the righteous! He has an entire refrain about the wonderful promises God makes. He speaks of being like a tree planted by the waters - about a harvest of fruit from his life - about un-withered leaves which represent vibrant life.
This sounds like "Satisfaction" to me! The "Stones" spoke of trying to get satisfaction based on what they heard on the radio or promises made on TV. Their mind was meditating on what the world said would satisfy - finding frustratingly that none of it did. 'Cause they would try and try and try and try . . . with that information - to be delighted and satisfied. In the end their refrain was, "I can't get no satisfaction." (Evidently they didn't get any grammar either)
Satisfaction comes in this world only in the ways that the Creator designed for it to come. This is why a much better song for us to sing is one where we are reminded that thinking much on His Word is the delight that brings delight. I can get some satisfaction - but only when I know what actually satisfies. Any other refrain will ultimately disappoint us with "no satisfaction."