As someone whos parents have the same birthday, as well as a sister, it’s not so cool after all.
Let me explain. The chances in real life is that if you have forty people in a room, 2 will have the same birthday. Many classes with even smaller numbers have two students with the same birthday. Why? Because there are certain months with more births (a discussion for another time and another place – see gmara megilla that chodesh haRivIi (Teves, when Esther was taken to Achashvarosh – chodesh sheNihena HaGuf MayHaGuf).
So the chances are not 1:365 but rather 1:40.
And anyway, my sister isn’t so special, (but of course, if you take into consideration her awesome brother, she is great)!!