Wow. They would have been little kids by now.
As the time since they left this earth grows longer and longer, I find that this day is more of a remembrance for me than it is a celebration of another milestone for them. I can't help but think this way. They are now ageless in Heaven and to celebrate a traditional birthday for them just doesn't make sense anymore.
This is the day that I gave birth to twins. 4 years ago already. They did actually exist on this earth. They did come for a purpose, that was accomplished in its fullness, as the Lord willed. I would have done it all over again, just for the exquisite pleasure of being their mom for the time I was given.
Happy Birth-day, my darlings. We remember you today.