A disappointing run

After having been pleased to do a big run of 11.3 miles last Saturday, I set out at 7 AM today, hoping to do the same route (though in the reverse direction). But I was disappointed to allow myself to cave in to fatigue (much more mental than physical), and hopped on the bus after 6.8 miles (about 1:11). Not that this is disastrous - but it is something I mustn't allow to continue if I want to build up the kind of mental toughness that will be necessary for the half-marathon on May 31.