Maybe

1David departed from there and escaped to
the cave of Adullam.

Who was David?

Besides being a man after God's own heart, he was a great warrior, who killed
Goliath, "slain 10,000", collected 100 foreskins for a dowry, and faced a lion and a bear.

And he is escaping?

Come on, what happened to "be a man and fight"?

Maybe he was afraid of Saul? I mean Saul has tried to kill him like 6 times so far. Or, could it be he's afraid of the ungodly in Saul? When you've stared evil in the face it can be frightening.

Maybe he feared more harm would come to Jonathan if he stayed.

Maybe he was just tired of the fight. Ever been there?

I'd like to think he was prompted by God and he followed those promptings.

Maybe God was calling David into the wilderness to prepare him before he took the throne, to shape his character.

Everything was being stripped away from David, family,
friends, and position; maybe he was learning that God is all you need. We usually don't learn that lesson until
God is all we have.

Maybe God was having David go into the wilderness because He knew that one day you and I would worship Him through singing songs based on David's feelings in the desert. Our best worship music comes from the Psalms David wrote while he was seeking refuge in the wilderness.

Maybe it was this:

And when his brothers and all his father's house heard it, they went down there to him. 2And everyone who was in distress, and everyone who was in debt, and everyone who was bitter in soul, gathered to him. And he became captain over them. And there were with him about four hundred men. 1 Samuel 22:1-2

Maybe those 400 misfits were so precious to God that He would send his best to minister and lead them, the future king and the man after God's own heart!

Whatever reason I'm glad he did because I can find comfort in each!