To prevent illness in later life, you should never have been born at all.
Progress is impossible without change, and those who cannot change their minds cannot change anything.
Beauty is all very well at first sight; but who ever looks at it when it has been in the house three days?
The power of accurate observation is frequently called cynicism by those who have not got it.
Some men see things as they are and ask why. Others dream of things that never were and ask why not.