Quotations from Person of the Century: Reality is merely an illusion, albeit a very persistent one. Imagination is more important than knowledge. Everything should be made as simple as possible, but not simpler. I never think of the future. It comes soon enough. Do not worry about your difficulties in Mathematics. I can assure you mine are still greater. Not everything that counts can be counted, and not everything that can be counted counts. (Sign hanging in Einstein's office at Princeton). The important thing is not to stop questioning. Curiosity has its own reason for existing. Anyone who has never made a mistake has never tried anything new. The only thing that interferes with my learning is my education. Education is what remains after one has forgotten everything he learned in school. The most incomprehensible thing about the world is that it is comprehensible. If A is success in life, then A equals X plus Y plus Z. Work is X; Y is play; and Z is keeping your mouth shut. Sometimes one pays most for the things one gets for nothing. Gravitation is not responsible for people falling in love. Common sense is the collection of prejudices acquired by age eighteen. Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe. In order to form an immaculate member of a flock of sheep one must, above all, be a sheep. Peace cannot be kept by force. It can only be achieved by understanding. We can't solve problems by using the same kind of thinking we used when we created them. I want to know God's thoughts; the rest are details. My religion consists of a humble admiration of the illimitable superior spirit who reveals himself in the slight details we are able to perceive with our frail and feeble mind. A person starts to live when he can live outside himself. A human being is a part of a whole, called by us "universe", a part limited in time and space. He experiences himself, his thoughts and feelings as something separated from the rest - a kind of optical delusion of his consciousness. This delusion is a kind of prison for us, restricting us to our personal desires and to affection for a few persons nearest to us. Our task must be to free ourselves from this prison by widening our circle of compassion to embrace all living creatures and the whole of nature in its beauty. The secret to creativity is knowing how to hide your sources. The hardest thing in the world to understand is the income tax.