Birthday

My birthday, a good and so happy one. 

I find myself staring by blankly at my wall. Wondering all but one thing. Why this birthday?

 Why must this one be considered one of my most special? I have nothing to give to this world yet all celebrate as a huge milestone. 

I do not understand, and maybe I'll never fully understand. But if you could spare some acquainted patience and kindly explain in that old voice, I might just be able to hold a firm grasp upon it.