Wait, are you saying the 21 pound pack was the one that made you cry? Because that makes zero sense to me. Carrying less weight should be easier on your body every single time, unless you packed it all wrong and had stuff digging into your back the whole trip. I get that a light pack can still hurt if your setup is bad, but a 32 pound pack on the JMT sounds like straight up misery to me. So what actually happened, did the light one have a busted hip belt or something?