The body was meant to sweat.  Sweat and relax.  Work and decompress.  I do more eating and commuting these days than anything else, but still – I remember the feeling.  It’s coming back to me like riding a bike.  The feeling of giving over to physical exhaustion.   Mental exhaustion is another thing entirely.  Mental exhaustion is when you’ve worked a puzzle in your head so many times that you literally need to stare off into space.  Which is a real thing, by the way, staring off into space – it’s a proven way for your brain to take five.   Physical decompressing is something different.  Your muscles give way.  Right now, I’m lying in a hammock and I can feel it in my…