Making Tracks
The child walks the train tracks easily. Although she must look down, the intervals between ties are well-suited to her gait.
As she grows taller, her strides become wider and she must either take a step too short or jump over a tie, thus missing it. This activity now takes complete concentration.
When she is old, her gaze is ahead and not down. She walks slowly, feeling the ground. The intervals are perfect once again.