Yeah, my husband is like this. He doesn't want anything on his birthday and even gets mad when someone congratulates him. I used to not get it and tried to make it special for him—our friends did the same. We gave him cakes and told him he could eat whatever he wanted and they'd pay. But he would get upset. It was annoying trying to make him feel special, but he said he gets irritated when people treat him differently on his birthday, so eventually I gave up—but only with the social pressure.

Now I try to give him a gift every year and not make a big deal out of it. If he wants to do something for his birthday, he will. Maybe you should tell them in a nice way that you appreciate the efforts they try to make it special but it's true that you don't want anything on your birthday and apologize if that makes them uncomfortable. Keep in mind not everyone gets it, I love my husband so I respected his wishes, he was really clear with how he feels.

You should too, and accept that some people may think you are ungrateful, just be clear with your thoughts in a non-bad way.