Why were the germans surprised on d-day?

The German Military, for the most part, did not expect the Allied invasion to land at the widest part of the English Channel, Normandy. They expected (again, for the most part, not entirely) the invasion was more likely to come at the Pas de Callais, the shortest point of the English Channel and therefore the shortest distance between France and England. This prompted German forces toreinforce the French beachhead at the Pas De Callais with much more men, supplies, defenses and defense positions than in Normandy. Only German General Rommel, placed in command of Normandy shortly before the D-Day invasion, suspected the Allied attack on the Normandy beachhead. There was not enough time, though, to reinforce Normandy to his liking.