In time, one becomes oblivious to the constants in ones environment.
Remember that scene from the Blues Brothers where Jake inquires of Elwood about the train that roars by a few feet from Elwood’s apartment?
Jake: How often does the train go by?
Elwood: So often you won't even notice it.
For those of you who go to San Onofre often, this scene of a few surfers and the gentle sound of the waves will be common to you. For the rest of you, you’ll notice something else.