Wet sneakers and muddy ...

Wet sneakers and muddy clothes are prerequisites for understanding the water cycle.
 David Sobel

Quotes from the same author

We tiptoed the tops of beaver dams, hopped hummocks, went wading, looked at spring flowers, tried to catcha snake, got lost and found. How fine it was to move at a meandery, child's pace.
 David Sobel
Exploration of the natural world begins in early childhood, flourishes in middle childhood, and continues in adolescence as a pleasure and a source of strength for social action.
 David Sobel