When you start a new game of Metal Gear Solid V, it asks you for your birthday. There's a reason for that -- the game actually uses it in a pretty sweet way.
Obviously, if you don't want to be spoiled on this, you should stop reading now!
abRobert has found that, if you happen to play Metal Gear Solid V on your birthday, you will at some point be greeted with this heartwarming scene:
Aww, Kojima. You shouldn't have.
I love how paranoid Big Boss is. C'mon buddy, it's just a surprise birthday bash!