The mind unlearns with difficulty what it has long learned.

It's not because things are difficult that we dare not venture. It's because we dare not venture that they are difficult.

It's not hard to find the truth. What is hard is not to run away from it once you have found it.

Difficulties strengthen the mind, as labor does the body.

It is not because things are difficult that we do not dare, it is because we do not dare that they are difficult.

Because a thing seems difficult for you, do not think it impossible for anyone to accomplish.