Preoccupation

No activity can be successfully pursued by an individual who is preoccupied . . . since the mind when distracted absorbs nothing deeply, but rejects everything which is, so to speak, crammed into it. Living is the least important activity of the preoccupied man; yet there is nothing which is harder to learn. . . . Learning how to live takes a whole life, and, which may surprise you more, it takes a whole life to learn how to die.
— Seneca