Random Footprints

Footprints lying in the sand,
left behind yesterday,
when today was still tomorrow.
A trail that shows from where they came,
and to where they might be going.
Whether standing, walking or running,
the trail shares this information.
But why the long trek through the sand?
Any suggestion is pure conjecture.
Nobody knows and, in another day or two,
the footprints will be gone,
having disappeared forever.