Unlike lawn mowing, deep thought whilst running, does not have the same risks - such as mowing your own feet or more seriously, mowing part of a shrub and having to explain this fact to the head gardener (She Who Must Be Obeyed).
It does have the risk of missing oncoming traffic - if you happen to cross a road (which, as I am in England this is highly likely) or share the route with other users. Horses are very large animals. Having been nearly run over by a trotting hunter am now taking this as a serious risk. The other is dog walkers, or rather the dog, who thinks either a) this is jolly good game to chase you or b) decided you are a risk and chases you. You then have to translate the barks - is that angry woof or playful woof? Either way stopping is often required - in order for the owner to recover the dog
It has given me a business idea. Exercise your dog - I run and the dogs chase me like idiots for a hour. But I think the chances of being bitten and losing dogs too high, for it to be viable.
These aside, running early in the morning - 7:00 AM, when most sensible people have just hit the snooze button on the clock radio, is peaceful. Morning dew turns spiders webs into silver necklaces, draped gaudily around branches. Soft golden light, playfully illuminates the woods and the turning leaves. You are alone - in fact I have even seen the milkman parked up and not moving.
I do have a music player thing with me, but do not use it. Firstly to listen out for horses or dogs, secondly as lost in thought.
And I find I very quickly retreat into thought, mainly as your legs begin to ache, you need to not think, "I have hardly gone any distance" or "why am I doing this?" or "I am far too old to do this".
The regular rhythm of feet hitting the leaf strewn path, the puffing steaming breaths, the jangle of keys in pocket sooth - like a train running on a track, like a steady hypnotic chant.
Having run the route many times, it is familiar, so you do not look so much- and if you were not thinking of something else, you'd be thinking of the pain in your legs, not on the fauna and flora (Deer mainly. No chance of hitting them, they run away as soon as see you).
Possibly this explains the series of trips and falls - not the poor state of the bridleways. Too busy musing on the unbearable lightness of being you miss the large tree root or pot hole and end up flat on your face (four times now in seven months). I have scabby knees and an interesting scar on my hand to attest to this.
But I still think deep thoughts. As it is space - my space - in a busy day, in a busy world. No e-mails to answer, no calls to answer, no one else to attend to. And really that is all one needs - time and space, possibly the most valuable commodity to anyone.