Dogen was a great reformer of Buddhism, and the founder of the Soto Zen sect of Buddhism. I came across a blog entry about him. A small portion is excerpted below. If you click here, you can read the whole thing.
Dogen speaks clearly of the mind that seeks the way with clarity and how to maintain the intensity of practice over time. We couldn’t ask for a world of more distraction than the one we currently inhabit. To maintain our commitment to practice over 50 or 60 years requires that we find a way to refresh ourselves daily; there is no formula that works for everyone. We each find our own life koans to keep us awake. And we are not in monasteries where the routine is set up for us, responsibilities provided, and practice times reliable. One cornerstone of waking up is meditation and finding the strength of commitment to the Way to return to our practice daily.
However far we “stray” it is always good to remember
The key to cultivating the Way is knowing that your own mind is originally pure, that it is neither created nor destroyed, and that it is free of discrimination. The mind whose nature is perfectly pure is your true teacher and superior to any of the Buddhas of the ten directions you might call upon.