@Wretched I feel this. Like having your 12th, 13th, and 16th birthdays forgotten. (Kid sister was born 10 days before my 12th, her first was just before my 13th, baby sister was born on my 15th birthday (but I had a bag of presents dropped on me as she left for the hospital), and since it was her first, I didn't so much as get a card for my 16th birthday). I basically ceased to exist on Christmas.
This past Christmas is the first since way back then, that all the kids were treated pretty equally. OF course, my kid sister is going to have her first kid, and my father is gone, so this year... I'll be surprised to be asked to come eat with them for Christmas dinner.