There is no such thing as a win-lose interaction; "only care about yourself" is a logically incoherent idea.
There is a lot to say on this topic, and it connects with many other areas. Here are a few things I'd like to examine:
- the scope of "interests" and "selfishness": not just material wealth, but everything we think of broadly to encompass a happy, joyful, prosperous life, and how that can mean different things for different people (without rendering the whole matter merely subjective whim/declaration)
- short-term versus long-term considerations of interests
- the harmony of genuine human interests
- genuine human interests versus contradictory / mutually exclusive desires
- how all interactions are ultimately either win-win or lose-lose, that anything purported to be win-lose is really lose-lose
- address examples like sports and games, with artificially created win-lose constraints
- "only care about yourself" / using "selfish" to mean cynically exploitative of others
- the interdependence of interests and how actually caring about yourself inherently requires caring about others; therefore, the contradiction inherent in the idea of being able to care about oneself without caring about others
- the equivocation of explicit focus (operative motive) and factual, long-term considerations (eg, parties negotiating to get the best outcome possible for themselves in a business dealing)
- how linguistic sloppiness (eg, "Oh, come on, you knew that what I meant was that he was pursuing short-term gain / whims at the expense of others and his true long-term interests!") encourages cultural misunderstanding of egoism
- the difference between knowing, in "cold economic calculus" terms, that others and their interests are a means to one's own interests and experiencing, emotionally, others as ends in themselves
- how caring about others and their interests is incompatible with altruism (in its serious ethical sense, not its sloppy colloquial sense)
- connection to psychology, emotional well-being, worthiness, shame-resilience: "To say 'I love you' one must first know how to say the 'I.''"
- connection to assuming positive intent and believing that people are generally doing the best that they can
- how interdependence of interests does not contradict the virtue of independence
- examples from business and product management
- Twitter's "respect the user's voice"
- integration of interests of company, employees, users, customers, developers