One of the very stupidest ideas in moral philosophy is the idea that morality has to run contrary to one's self-interest. Such philosophers typically reduce self-interest to immediate material self-interest to make their case.
But I live in a house I could not have built by myself. I eat food I could not have grown myself. I drive a car I could not have built myself. I use a computer I could not have built myself, and could not myself have discovered the subtle, scientific principles on which it's constructed. Even though I'm a computer programmer, I use software I could not possibly have had the time to write myself. I see a physician who knows more about my body than I could have learned myself. There are soldiers, police and lawyers who protect me in ways I cannot protect myself. I've been educated, edified, entertained and amused by thousands of books, plays, movies and television shows I could not have written or produced myself. I've been taught a body of knowledge I could not have created myself by teachers, scholars and scientists.
The notion that these items do not accrue to my self-interest is absolutely idiotic.
And yet all of these benefits rely on the moral beliefs both I myself and the members of my society have adopted: Don't steal, don't hit people, don't lie. Without these moral beliefs, we would have no cooperation, no society, no civilization: We would, as individuals, be little more that brute animals living on the brink of starvation.
Yes, I have to "sacrifice" my immediate, material self-interest. I cannot simply take what I want from the grocery store: I have to pay for it. I cannot simply occupy a house that pleases me, I have to pay rent or a mortgage. I cannot simply punch someone who annoys me.
Well whoop de fucking do. Living in a civilized society? Or living in a cave, eluding tigers and killing antelopes with rocks? You do the math.
Morality is contrary to self-interest my house-living, car-driving, grocery-store-shopping ass.