I am a firm believer in the "do unto others" rule. I spent my early marriage days drilling that into my husband's head, who was brought up believing "do whatever gets you what you want".
I find comfort in knowing that both Bob (that's what we call Junior these days...long story) and I have lived most of our married life this way. We treat the people we love with respect. We do things for them, without expecting anything in return. That was how I was raised. This is how we are raising our kids. Good deeds don't come with a price tag, or expectations of anything in return.
So, as you live your life, remember that if you treat the people around you like crap, in the end, you end up all alone, with only your dirty diapers keeping you company.
And that just might be exactly what you deserve.