When my daughter was very young, we had quite a long bedtime ritual. Every night, we concluded by saying Shema and singing Ha’Malach. She was nervous of being left alone (with her two siblings) in their room to go to sleep. I always reassured her by saying that there is nothing to worry about. When she says Shema, she asks Hashem to stay with her and protect her through the night.
One night, as I was leaving the room after all of the good-nights, she said to me, “Ima, how did you ever go to sleep when you were little? You couldn’t say Shema.” (I converted to Judaism as a young adult.)
She was four years old and she already knew how lucky she was!