Tomorrow is my birthday, that's right, my birthday and not yours. So why do you want to congratulate me? It's mine, I know about it, I don't need your input.
In my partner's culture everybody wants to know about your birthday, they will phone you and congratulate you, they will expect you to have a party, at home and in the office. On your wonderful birthday day you will answer the phone and serve food and drinks. Oh, what a wonderful day! Your boss will shake your hand too.
In my culture adults keep quiet about their birthdays, you can celebrate your round ones, those with a zero. I fully intend to celebrate my 190th birthday.