It is good to have a goal, but bad to let your goal have you. Focus is good, but focus that is too narrow becomes blindness.

The Stoic Emperor

There can be no initiative if one has fear, and fear compels us to cling to tradition, gurus, etc.

Bruce Lee

Attachment leads to suffering.

Buddha

Observe all men, thyself most.

Benjamin Franklin

One should not be happy or distressed over desirables and undesirables, knowing that such feelings are just created by the mind.

A.C. Bhaktivedanta Swami Prabhupada

The mind in itself can make a heaven of hell or a hell of heaven.

John Milton