Happiness depends more upon the internal frame of a person's own mind than on the externals in the world.

The world may be utterly crazy, and life may be labour in vain; But I'd rather be silly than lazy, and would not quit life for its pain.

If you have a really good idea, stick to it, but be flexible on how you get there. Be stubborn on your vision but flexible on the details... People who are right a lot change their mind... They have the same data set that they had at the beginning, but they wake up, and they re-analyze things all the time, and they come to a new conclusion, and then they change their mind.

All battles are first won or lost, in the mind.

Complaining is not a strategy. You have to work with the world as you find it, not as you would have it be.

There is no illness of the body except for the mind.