The device in which you are reading this article will be junked in a couple years. The hand that is holding it won’t be there in the next hundred years. The eyes that are reading it will stop seeing one day.
Everything changes. The sun, earth, moon—everything. Our bodies, houses, mountains, roads, rivers, forests, they are changing. By the time you finish reading this article, millions of cells in your body will have changed.
It rarely occurs to us that our cars will stop running one day and our loved ones will either go away or die. Even if they stick around, the ‘love’ will change. We don't realize it, because it seems so solid, the whole world seems so intact.
But some people can see it.
Impermanence was the trigger that caused Prince Siddhartha to leave his illusive world one full moon night. We know the story—He saw an old man, a sick man, and a corpse on his tour to the town. He came to know about change and suffering. He realized that his own body that he held so dear, and his wife and son and father whom he loved so much, would also change. They would grow old, get ill, and die one day. That realization changed not only his life, but also those of countless more people in the past two and half millennia.
After enlightenment, Siddhartha spent his life teaching people about impermanence. He told them that failure to see impermanence caused them suffering. He said even a few seconds of meditation on impermanence would bring people infinite merits.
An inspiring story. But chances are, we simply discard it as something great happening only to great people. It cannot affect ordinary people like us. We cannot be Buddhas.
Or there may be denial altogether—Prince Siddhartha was already enlightened; he didn't need to see suffering to free himself from worldly allures. We see old and sick and dead people all the time, but nothing happens. See, we are still safe in our homes, we still have our morning coffee, and we have all the worldly duties, and friends to attend to. Come on, it must have been something deeper and bigger for him.
The mind is a magnificent trickster. Somebody saw impermanence and the whole world changed. He lived it and preached it. A great event happened in the history of mankind. But our mind doesn’t like the idea that things change, and ensures that we don’t learn it—neither from the person’s life story that signifies the realization of change, nor from his direct teachings. No wonder that we are not Buddhas.