About a month ago, I caught a 24-hour flu virus. I went to bed one night feeling fine. The next morning, I woke up to find that my digestive system had stopped working. I had to throw up the food my body wasn't dealing with. I couldn't get warm, and I had so little energy that an ill-advised 20-minute walk to campus required a two-hour nap to recover. By the afternoon, I could barely stand up.
It happened to be one of the days that Alex oniugnip was in town for his Ph.D. recruitment visit. He took me home and put me to bed under a pile of blankets, where I slept like a rock. Several hours later, he woke me up in the sweetest, gentlest, most gradual way possible: by taking my left hand in his and gently picking up each of my fingers, then setting them down, very slowly, one at a time, over and over.
Here's what it felt like. A continuation-passing interpreter takes three arguments. I have four fingers -- more than enough. One at a time: Pick up. Hey. Are you okay? Are you what you're supposed to be and where you're supposed to be? Yes. Okay. Set down. Next finger. My fingers were walking through the evaluation of an expression, one recursive step at a time. When it was done, I was awake and suffused with the feeling of being completely taken care of.