I am running through the halls of Paumanok Elementary School. I'm not late. Tardiness hasn't occurred to me yet.
"No running in the halls!" is a constantly necessary reprimand for children, while conversely it is quite difficult to get an adult to run. He or she must be under some grave duress like chasing a bus, or being chased. Otherwise one might plan a run in some tiny crook of the schedule, which he or she often has difficulty keeping to. Children, however, without any known destination, will run wild.
It is not uncommon for a young student to run to his next class and then once there, frantically begin devising the fastest means of escape. The place he ran to isn't so different from his expectations because he hadn't any, except maybe that what awaited would be more new. It is at a certain age a type of surprise that arrivals should be so mundane; that so much could have been expected.
Running seems to slow as destinations become clear, and maybe that's why adults walk; they know where they are going. If we could pinpoint the exact moment when a kid chooses not to run, but instead takes pace, I believe we will have identified in that moment his entry into adulthood, and I think it is probably the same moment where a kid who formerly "couldn't wait," can.