My understanding of this is that if you invite people out for your birthday dinner that you're supposed to pay for all your guests. However after my last birthday dinner at which I paid for all my guests, some people were like 'you're not supposed to pay for your own birthday dinner' and 'if anything, the guests should be paying for you!' I have no idea whether this is like some sort of cultural thing, but if you ask people to go to dinner with you then it's rude to make them pay their own way.. especially if where we're going is kinda fancy.
Am I super old-fashioned or something? What's the norm?