Human nature may be mostly about caring about oneself and about one's own. It may be mostly about promoting self-interest.

Islam, however, is mostly about caring about others.

And that is largely because there is a perfect equation in Islam, given in a Hadith, that quotes Allah as saying -- in my broad paraphrase:

So long as an individual is engaged in helping other human beings, 
and promoting their wellbeing, God Almighty will be engaged 
in helping such individuals and promoting their wellbeing.

END