Why was "Case Yellow" more successful than "Sea Lion"?

"Case Yellow" was the code name given to the initial
German push through the Ardennes and into France.  Sea Lion was the name given to the
invasion of England that never actually occurred.  Case Yellow, of course, succeeded
where Sea Lion was never even truly attempted.  The major reason for this was the German
inability to destroy British sea and air forces.

Case
Yellow was successful because the German army was much more prepared and had much better
tactics than the French and British.  German mechanization and use of combined arms was
beyond anything the Allies had conceived of.

Sea Lion,
relied on Germany domination of the English Channel and the skies above it.  This
required the destruction or distraction of the Royal Navy (much stronger than Germany's
navy) and of the RAF.  Neither of these things was done successfully.  Because the
British continued to have significant sea and air power, the invasion was deemed
impossible and was called off.