Alyosha’s sinful laugh after reading the love letter. And then the laugh is repeated, it isn’t sinful any longer. With the first laugh he seems to be laughing at the girl who is in love with him. With the second laugh he’s laughing at all of us. “These unhappy and turbulent souls”, we are all lost but we will find joy in God. It doesn’t matter how little we know God, our anxieties come to nothing because He exists. And so a light and joyful laugh not only at everyone else’s worries but at his own too, the troubles of the day that even brought him to tears earlier that evening.
When he got to the monastery he’d regretted having forgotten even “for one instant” Father Zossima. Perhaps he’d forgotten God that evening too. To be troubled by such worldly cares! And all it takes is laying down on your hard bed in the monastery to remember again your place in the world and see that none of it matters, or if it matters it’s out of your hands, and you will get your share of joy however you fret.