safety. as in, can you describe the person you just ran by? if they were running toward you, did you make eye contact? did you greet each other? if you passed them, were they working hard or taking it easy? did they fall behind or keep pace with you now that you're ahead? basically what could you say about them to the police if they tried to mug you...while you're alone...in the woods/path/park/trail?
there are any number of details that you should be alert to for the critical reason of keeping yourself safe. and for god's sake, do not wear both ear buds in with the volume turned up. don't get 