This usually happens while I'm running. Particularly my long runs on the weekend, when I have considerably longer chunks of time to distract myself from the actual work my body is doing. I've also "written" lots of emails, to-do lists, and made all sorts of plans for myself. All in my head. That all get left on the trail.
My long runs have gotten progressively longer, as I've now registered for not one, but TWO Half-Marathons this spring! One in March, close to home, and one in April at the Outer Banks. I had been increasing my mileage pretty slowly at the end of last year, and then I realized I had to step it up a bit. So, starting in January, I increased my long run by 1/2 mile each week. At this writing, I finished a long run of 10 miles on Sunday, and will do 10.5 next weekend. Sounds crazy, right!?!?!
I have developed some rules and mind games while I run, to keep me
And if all else fails, I count my footsteps.