"Then Eli perceived that the LORD had called the boy."
After that, Eli told Samuel to answer the Lord's voice...and when he did, God used him for great things.
What I hadn't seen before was that for Samuel, it took someone to perceive that God had called him.
Just another good reason to keep our hearts open--God calls young people! And sometimes they just need someone to perceive that calling...so God can use them for great things.