and she would first be smiling the big closed-mouth smile she smiles, then that big

small-toothed smile she smiles, then she would be laughing, someone would say something funny and she would laugh that way she laughed, silently, crazily, out of breath, it was so funny whatever someone said, who said that funny thing?  Who?  Maybe I said it, maybe I said it and made her laugh like sometimes we could, really bust her up, so that it was just killing her, this laughing, her eyes struggling to stay open, to see, because when she laughed, my mom almost immediately teared up, and had to wipe her tears with the side of her forefinger--Oh that's when you knew you had really said something funny, when she would be crying, wiping her eyes, you had her then, you really wanted that, there was no greater thing, no achievement so great, so stirring, you tried to play it casual, deadpan, but you were so proud and thrilled, watching her, you wanted her first to say Stop! Stop! because you were so funny but you would continue because you wanted her to laugh more, to really laugh until she would have to rest, to half collapse on the kitchen counter while you were sitting at the table after school, Oh you're awful! she would say.  Stop!  Oh but to see her laugh you would say anything, and she so loved a good laugh at someone's expense--Bill's, Beth's, yours, her own, and at that moment everything would be wiped away, all the times you feared her or wanted to run away, or wondered how she lived with him, protected him, you wanted only her laughing like she did when she was on the phone with her friends--Yes! she would shriek, Yes! Exactly!--then afterward she would sigh, breathing heavily and say Oh that's funny.  God, that's funny.
from pages 346-347 of Dave Egger's A Heartbreaking Work of Staggering Genius