It is a universal law – have no illusions – that every creature alive is attached to nothing so much as to its own self-interest. - Epictetus

Remember to act always as if you were at a symposium. When the food or drink comes around, reach out and take some politely; if it passes you by don't try to pulling it back. And if it has not reached you yet, don't let your desire run ahead of you, be patient until your turn comes.

For no man is a slave who is free in his will.

Do your own useful work without regard to the honor or admiration your efforts might win from others. There is no such thing as vicarious merit.