Man is not worried by real problems so much as by his imagined anxieties about real problems.
Don't seek to have events happen as you wish, but wish them to happen as they do happen, and all will be well with you.
The mind that is anxious about future events is miserable.
We are more often frightened than hurt; and we suffer more from imagination than from reality.
If you are distressed by anything external, the pain is not due to the thing itself, but to your estimate of it; and this you have the power to revoke at any moment.