"The hardest thing in the world to understand is the income tax."
"A person starts to live when he can live outside himself."
"Sometimes one pays most for the things one gets for nothing."
"Anyone who has never made a mistake has never tried anything new."
"Gravitation is not responsible for people falling in love."
"Common sense is the collection of prejudices acquired by age eighteen."
"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."
"Everything should be made as simple as possible, but not simpler."
"Anyone who doesn’t take truth seriously in small matters cannot be trusted in large ones either."