> "what would happen if everyone did X?" I don't understand when this rule should/should not be used. Clearly, the rule breaks down in certain situations. For

> "what would happen if everyone did X?" I don't understand when this rule should/should not be used. Clearly, the rule breaks down in certain situations. For example: What if everyone decided to go into tech? That's not really good for society since we need things like doctors, but some people do need to go into tech.