Cows first fill their stomachs with grass and other food. Then they settle down for a good, long chew. They bring the food back up from their stomachs and rework what they've already eaten, assimilating its goodness and transforming it into rich milk. Not if they want to give good milk. The writer of Psalm 119 obviously did a lot of mental chewing as he read God's Word.
Meditation is more than reading the Bible and believing it.
It's applying Scripture to everyday life. God's Word is not meant to be fast food. Take time for a good long chew. To be a healthy Christian, don't treat the Bible as snack food.