Saul believes that David has been summoned to become a court musician. God had other plans. God used this time to grow David and prepare Him for leadership. He studied under the king before he assumed the position. David also had the opportunity to make some divine connections, especially with Johnathan.
Often times we don't understand why God places us where He places us or why. It can seem like a minor change but sometimes these are major set-ups.
In order to be more teachable, we must work to fully rely on God. This does not come natural for Christians because we have a desire to understand everything. Relying on God comes through prayer, fasting, and studying the word of God. Look at what He has done before and recognize that He is the God who does not change. He is faithful to never leave us nor forsake us. God help us to rely on you even when we don't understand what you're doing. In Jesus name!