W. Somerset Maugham said this quote

“ I have nothing to do with others, I am only concerned with myself. I take advantage of the fact that the majority of mankind are led by certain rewards to do things which directly or indirectly tend to my convenience.’‘It seems to me an awfully selfish way of looking at things,’ said Philip.‘But are you under the impression that men ever do anything except for selfish reasons?’‘Yes.’‘It is impossible that they should. You will find as you grow older that the first thing needful to make the world a tolerable place to live in is to recognise the inevitable selfishness of humanity. You demand unselfishness from others, which is a preposterous claim that they should sacrifice their desires to yours. Why should they? When you are reconciled to the fact that each is for himself in the world you will ask less from your fellows. They will not disappoint you, and you will look upon them more charitably. Men seek but one thing in life—their pleasure. ”