I did three Vipasana retreats back in the 90s in the Shelburne Falls, MA. center. The OP kind of glosses over what was for me, on my first retreat, the single

I did three Vipasana retreats back in the 90s in the Shelburne Falls, MA. center. The OP kind of glosses over what was for me, on my first retreat, the single most enduring issue: physical pain. Yes, all experience is transient, but that drill driving into your knee is constantly impermanent, as in, not much respite (btw, doesn't matter how you sit, cross legged, kneeling, or in a chair, when the body is made still for @14 hours a day, der pain cometh ;-)) Escape in day dreaming, meals, and sleep is par for the course, as is going to your room to meditate (forbidden, a monitor would come and bring you back to the hall), and doing yoga, thai chi or other practice to break the monotony/limber up the sore joints. Saying that, if you've got time and are of sound mind (have to sign a waiver to that affect), go for it, it's a truly unique experience -- things are not as they seem, the concrete you that you thought you were, doesn't exist, at least not permanently ;-)