Thoreau wished to engage in an experiment of “simple living”, and he remained at Walden for two years.
He lived alone at Walden, but not as a hermit. Amongst his regular visitors were several famous writers, including the Emerson family, the Alcotts, and the Hawthornes. He wrote of the “regular salutes of laughter” in his home when his friend the poet Ellery Channing visited.
Thoreau explained he went into the woods "to suck the marrow out of life."
I went to the woods because I wished to live deliberately, to front only the essential facts of life, and see if I could not learn what it had to teach, and not, when I came to die, discover that I had not lived.
While at Walden, Thoreau wrote several of his best remembered works, including the first draft of his masterpiece Walden. He wrote: “It is the sum of all wisdom not to do desperate things. The great mass of mankind lead lives of quiet desperation.”
The surface of the earth is soft and impressible by the feet of men; and so with the paths that the mind travels. How worn and dusty, then, must be the highways of the world, how deep the ruts of tradition and conformity! I did not wish to take a cabin passage, but rather to go before the mast and on the deck of the world, for there I could best see the moonlight amid the mountains. I do not wish to go below now.
I learned this, at least, by my experiment, that if one advances confidently in the direction of his dreams, and endeavours to live the life which he has imagined, he will meet with a success unexpected in common hours. He will put some things behind, will pass an invisible boundary; new, universal, and more liberal laws will begin to establish themselves around and within him; or the old laws be expanded, and interpreted in his favour in a more liberal sense, and he will live with the license of a higher order of beings. In proportion as he simplifies his life, the laws of the universe will appear less complex, and solitude will not be solitude, nor poverty poverty, nor weakness weakness. If you have built castles in the air, your work need not be lost; that is where they should be. Now put the foundations under them.