Anybody can become angry - that is easy, but to be angry with the right person and to the right degree and at the right time and for the right purpose, and in the right way - that is not within everybody's power and is not easy.

Aristotle

A friend to all is a friend to none.

Aristotle 

Stay Hungry. Stay Foolish.

Steve Jobs

Gravitation is not responsible for people falling in love. 

Albert Einstein 

I am the greatest, I said that even before I knew I was.

Muhammad Ali 

I fear not the man who has practiced 10,000 kicks once, but I fear the man who has practiced one kick 10,000 times.

Bruce Lee