My mom sent me an SMS to remind me that I came home one day and excitedly shared "'Yellow River' by IP Freely" (I believe it was something in MAD Magazine). I was laughing so hard that I could barely say it. For months afterward, whenever I thought of it (or read that issue of MAD, purchased because of it), I laughed like some sort of maniac.

That was shared by a girl in my class named Cynthia. She seemed to be almost twice my height and more than twice my weight. The next year I changed schools and I don't think I ever saw her again. But she used to share lots of funny things (which often seemed to be sourced from MAD).