You're not alone Conne. I don't celebrate my Birthday either.
In my last job, I would either take the day or the whole week off work. I once had to work on my Birthday, and one of the Till staff was doing the time cards for the week - if she hadn't then she would never have told the Manageress. I even told my Sister and Nephews NOT to plaster it all over Facebook - I prefer a text message to my mobile. I have had some strange looks from people when I tell them that I don't celebrate it. It's just another day of the week to me.