It mellowed his world.

It was half an ache, half a steady and undying pain, but it drew Life nearer to him than he had ever known it before.

His love for the sun and the sky, for the trees and flowers and all growing things of the earth was more worship of the divine than a love for physical things, and each day he felt it drawing more closely about him in its comradeship, whispering to him of its might, and of its power to care for him in the darkest hours of stress that might come.
He did not travel fast after he had reached the decision to go to Yellow Bird's people.

And he tried to imagine, a great deal of the time, that Nada was with him.

He succeeded in a way that bewildered Peter, for quite frequently the man talked to someone who was not there.
The slowness and caution with which they traveled developed Peter's mental faculties with marvelous swiftness.