At the beginning of meditation training thoughts will arrive one on top of another, uninterrupted, like a steep mountain waterfall. Gradually, as you perfect meditation, thoughts become like the water in a deep, narrow gorge, then a great river slowly winding its way down to the sea; finally the mind becomes like a still and placid ocean, ruffled by only the occasional ripple or wave.
Sogyal RinpocheSamsara is the mind turned outwardly, lost in its projections. Nirvana is the mind turned inwardly, recognizing its true nature.
Sogyal RinpocheAsk yourself these two questions: Do I remember at every moment that I am dying, and that everyone and everything else is, and so treat all beings at all times with compassion? Has my understanding of death and impermanence become so keen and so urgent that I am devoting every second to the pursuit of enlightenment? If you can answer "yes" to both of these, then you really understand impermanence.
Sogyal Rinpoche