Birthdays

Everybody has something that defines them.

Some people are known for their ability to run very fast, or invent things, or fit 26 oddfellows into their mouth at once (good one Dad).

But my thing is birthdays.
I celebrate them.
Lots.  

From a young age, I have combined my love of fractions with my love of birthdays.
Thus, I not only celebrate whole birthdays, but also 1/2 birthdays, 1/3 birthdays, 1/4 birthdays, and every other 1/12 fraction that occurs in between.
(It hasn't always been easy.  So many birthdays have passed by unnoticed and uncelebrated by the world.) 

But just three days ago, I had a WHOLE birthday.  It was terribly exciting.
I told everybody I encountered that it was my birthday.  The man at the bank was congratulatory.  The maintenance man at work was less enthused.  The courier was downright rude.  But the owner of the cafe gave me FREE CAKE with my birthday lunch!  (Another thing that defines me is cake).

Thus, I would postulate that 1/4 of people will offer spontaneous presents when informed that x number of years ago, on this day, you were born!
Birthdays are a numbers game: the key is telling as many people as possible...

And they want to know.  They really want to know.  There's nothing worse than forgetting a secretive person's birthday and then realising you had lunch with them that day and talked mostly about yourself. 
There are almost 7 billion people in the world.  If each one of them is, like me, celebrating twelve birthdays per year, then that means there are 63 billion birthdays every year.
I CANNOT BE EXPECTED TO REMEMBER 63 BILLION BIRTHDAYS.
YOU HAVE TO TELL ME.
And in return, I will tell you...

(don't worry if you missed it, I have another one in only 28 more days)