"Walden" by Henry David Thoreau. Truly did change the way I think about the world, the fundamentals of what is required for a free life, and how humankind so often tethers itself to a life of misery. Consider, for example, this quote: "The farmer is endeavoring to solve the problem of a livelihood by a formula more complicated than the problem itself. To get his shoestrings he speculates in herds of cattle. With consummate skill he has set his trap with a hair spring to catch comfort and independence, and then, as he turned away, got his own leg into it."

Or perhaps this: "I see young men, my townsmen, whose misfortune it is to have inherited farms, houses, barns, cattle, and farming tools; for these are more easily acquired than got rid of. Better if they had been born in the open pasture and suckled by a wolf [...] Why should they eat their sixty acres, when man is condemned to eat only his peck of dirt? Why should they begin digging their graves as soon as they are born? They have got to live a man's life, pushing all these things before them, and get on as well as they can. How many a poor immortal soul have I met well-nigh crushed and smothered under its load, creeping down the road of life, pushing before it a barn seventy-five feet by forty, its Augean stables never cleansed, and one hundred acres of land, tillage, mowing, pasture, and woodlot!"

I loved it, and I thank him constantly for reminding me of what it is to be born free.