Henry David Thoreau spent two years, two months and two days in a cabin by Walden Pond, and kept a ledger of what the experiment cost, down to three quarters of a cent. He gave his reason for going in one famous sentence: he wanted to live deliberately, and not to find out, when he came to die, that he hadn't lived. Everything in it hangs on that one word, deliberately, which for him meant choosing what he faced and what he left out. You don't need a cabin for that. A lot of any week gets decided before you've chosen anything, by whoever asked first. Before lunch, look at one plan for this weekend and ask whether you actually picked it.
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.
Henry David Thoreau, Walden (1854), "Where I Lived, and What I Lived For"