All.

Nick looked at the burned-over stretch of hillside, where he had expected to find the scattered houses of the town and then walked down the railroad track to the bridge over the river. The river was there. It swirled against the log spiles of the bridge. Nick looked down into the clear, brown water, colored from the pebbly bottom, and watched the trout keeping themselves steady in the current with wavering fins. As he watched them they changed their positions by quick angles, only to hold steady in the fast water again. Nick watched them a long time.

He watched them holding themselves with their noses into the current, many trout in deep, fast moving water, slightly distorted as he watched far down through the glassy convex surface of the pool, its surface pushing and swelling smooth against the resistance of the log-driven piles of the bridge. At the bottom of the pool were the big trout. Nick did not see them at first. Then he saw them at the bottom of the pool, big trout looking to hold themselves on the gravel bottom in a varying mist of gravel and sand, raised in spurts by the current.

Nick looked down into the pool from the bridge. It was a hot day. A kingfisher flew up the stream. It was a long time since Nick had looked into a stream and seen trout. They were very satisfactory. As the shadow of the kingfisher moved up the stream, a big trout shot upstream in a long angle, only his shadow marking the angle, then lost his shadow as he came through the surface of the water, caught the sun, and then, as he went back into the stream under the surface, his shadow seemed to float down the stream with the current, unresisting, to his post under the bridge where he tightened facing up into the current. Nick’s heart tightened as the trout moved. He felt all the old feeling.

Ernest Hemingway, from "Big Two-Hearted River Part I"