Why can’t Josh sleep before the big game in the poem “The Main Reason I Can’t Sleep”?

He is worried about the game.
His brother is on the phone with a girl.
The stubble on his head is itchy on the pillow.
He is worried about his dad.

The main reason Josh can't sleep before the big game in the poem "The Main Reason I Can't Sleep" is that he is worried about the game.