Living slowly ("deliberately") was one of Thoreau's themes. He mixes this theme with another favorite, that of simplicity. (And if you ask me, it's long past time we revive Walden and make it required reading in our schools; we've lost sight of Thoreau's most important insights.)
In chapter 2, he says, "Why should we live with such hurry and waste of life? We are determined to be starved before we are hungry. Men say that a stitch in time saves nine, and so they take a thousand stitches today to save nine tomorrow." He goes on to say that most of our work is inconsequential, but we're busy all the time, and furthermore, live to learn the latest news, always the latest news. In essense, he's saying that we have lost sight of ourselves, we're too busy, and we don't even know who we are anymore.
Later in the same chapter, he says, "When we are unhurried and wise, we perceive that only great and worthy things have any permanent and absolute existence, that petty fears and petty pleasures are but the shadow of the reality. This is always exhilarating and sublime." This is in the context of how we hurry through life and are deluded into believing most of life matters when in fact, little of it really does. We are so busy we no longer know what it is to live, to just be.
And so, Thoreau went to the woods to live deliberately....