It's impossible to attain the Tao since the Tao's not something. It is everything and what gives rise to everything, even thoughts about the Tao. "The Tao" is just what Lao Tzu chose to call "it", but all concepts and words are arbitrary. It is only when one "sheds" one's ego and its assumptions and mental images of the world that one sees the world for what it "truly is". This state is often reached through meditation, and once it is experienced something just "clicks". All inhibitions are gone. One just happens to say the right words at the right time, and there's an immense feeling of harmony and relief. It is a feeling of being exactly where one is supposed to be, for it would literally be impossible to be somewhere else.
In order to attain the Tao one must feel it, not think it.