1/2 mile of torture

Got in 4 miles on the 1/2 mile loop in our 'hood yesterday.  The mind is a crazy thing.  I've finished a couple of hundred milers......can spend many hours on the trail on any of the myriad trails in the Austin area but it's ALL I can do to do 8 frickin laps around that darn loop.  If it was an event I wouldn't give a second thought to running around it for 12hrs but not on a casual afternoon run.  MADNESS