OK, now hear me out and let me explain.
From a young age, we are all taught not to be selfish. We are taught to put other's needs above our own, and sometimes: it stuck. Our parents and teachers and soccer coaches thought it was a great idea. We were being taught to not be assholes; but now, some of us are caught with the issue that we don't know how to be selfish.
They drilled it into our heads so much that we don't know how to care for ourselves. We don't know how to be selfish, but we need to. We are all old enough to know when to put other's needs above our own, but we need to do the reverse. It's for our own good.
So be selfish.
Be selfish because the world was not taught that being selfish was a bad thing. Be selfish because the only person on the planet concerned about your wellbeing is you. I'm sorry to say it, but it's very much true. No one is going to help you. No one is going to be concerned about you, except for you.
Be selfish. If you don't want to do something, don't do it for someone else. Don't drop everything for someone else, because often don't do the same for you. Be nice, and be pleasant, and absolutely help them out, but do not expect them to do the same.
Be selfish, and be self-sufficient, and be able to take care of yourself because others won't do it for you.
Be selfish and look out for yourself.
Be selfish but be sweet and pleasant and a good friend.
But be your own best friend.
Know what you need more than anyone else.
Be your own advocate.
Be selfish, and be selfish until you don't have to be anymore.