This beautiful ocean carries with it loads of poisonous floatsam and jetsam. That poison is diluted. That poison is diluted by the sea. But once the ocean rolls out, it leaves the shit behind, inside the body. It takes as well as it gives, washes away the endorphins, the pain resistance centres. They take a long time to get back.
More short term sea. More long term poison.
Its what it takes to get out of habit.