Nothing awakens a reminiscence like an odor

A faith is a necessity to a man. Woe to him who believes in nothing.

Doing nothing is happiness for children and misery for old men.

Nothing else in the world... not all the armies... is so powerful as an idea whose time has come.

There is nothing like an odor to stir memories.

...his sleep, though deep as death itself, was not dreamless this time, but threaded with ghostly wisps of dreams. These wisps were clearly recognizable as scraps of odors. At first they merely floated in thin threads past Grenouille's nose, but then they grew thicker, more cloudlike. And now it seemed as if he were standing in the middle of a moor from which fog was rising. The fog slowly climbed higher. Soon Grenouille was completely wrapped in fog, saturated with fog, and it seemed he could not get his breath for the foggy vapor. If he did not want to suffocate, he would have to breathe the fog in. And the fog was, as noted, an odor. And Grenouille knew what kind of odor. The fog ws his own odor. His, Grenouille's, own body odor was the fog.

And the awful thing was that Grenouille, although he knew that his odor was his odor, could not smell it. Virtually drowning in himself, he could not for the life of him smell himself!