A story of sleep
I once heard the following story.
A good man had spent his whole life cultivating wisdom, and his mindfulness was vast. However, he sometimes forgot his purpose and let his mind lapse. He reasoned that, balanced against his good qualities, his lapses were only a small fault.
He was rather fond of sleep and therefore missed opportunities to advance his knowledge and understanding. Then he died.
On examinig his conscience he thought his qualifications high enough to enter Heaven. When he arrived at the gates they were shut, but a voice addressed him, saying, "Be watchful; for the gates will open once every hundred years." He settled down to wait, excited at the prospect. But, deprived of people with whom to converse and pass on his knowledge, he found his capacity of attention was not enough. After watching for what seemed like an age, his head nodded in sleep. For an instant his eyelids closed. In that infinitesimal moment, the gates yawned open. Before his eyes were fully open again, they closed . . . with a roar loud enough to wake the dead.