I mean, people don't come to birthday parties because they feel obligated. Or at least they shouldn't. They come to birthday parties because it's fun.

If you invite your friends to celebrate with you, they will have a good time. So you're not being selfish. You're inviting your loved ones to SHARE an enjoyable experience with you.

It's not that you're dragging them to celebrate you, purely for your benefit. You're asking them to share a joyful experience WITH you, to share in YOUR celebration of yourself.