  By considering an optically denser medium with a flat surface, but with
natural roughness instead of abstract geometrical boundary which leads to
mathematical discontinuity on the boundary of two adjacent stratified media, we
have thus established the importance of considering physical surfaces; and thus
we studied the Goos-H\"{a}nchen (GH) effect by ray-optics description to shed
light on parts of this effect which have remained ambiguous. We replaced the
very thin region of surface roughness by a continuous inhomogeneous
intermediary medium. Applying Fermat's principle for the incident light ray,
few fundamental questions about GH shift are more convincingly addressed which
are in excellent agreement, even with the most details of the experimental
results.
