Two related thoughts.
First, early walks on the beach means there are no obstructions, people, beach blankets, umbrellas etc. Distant piers appear only a short walk away, but with nothing but sand to mark the space, seem to take forever to reach.
Second, looking at ones feet while walking through the surf is a good way to be deceived about your progress, even dizzying. Instead you have to focus on the shore to keep from faltering.
How we measure time is tricky.