We do not quit playing because we grow old, we grow old because we quit playing.

It is the province of knowledge to speak, and it is the privilege of wisdom to listen.

What lies behind us and what lies before us are small matters compared to what lies within us.

Fame usually comes to those who are thinking about something else.

The young man knows the rules, but the old man knows the exceptions.

A man may fulfil the object of his existence by asking a question he cannot answer and attempting a task he cannot achieve.

Love is the master key that opens the gates of happiness.