Don’t expect people would do the same way you did for them.
People are people. They commit mistakes. They’re not perfect. Above all, they have their own life, their own business. You cannot blame them for a reason that they don’t love you. It’s their choice to love you or not to love you. It’s their choice to be with you or be with someone else. But it’s your choice whether to assert yourself to those people who don’t even care or to build your own life, your own happiness.