Little things mean...

Today is my sons birthday. I have found myself crying on more than a couple of occasions (out of site of course). The reason...

between my a/family and my real family, at least 24 adults in all, not one card. I know it sounds pathetic to cry over something so small. I am not even sure why it hurts so much. My sons attitude was 'so what'. So why did it tug my heart, no rephrase that, why did I feel my heart had been torn out and trampled on?
If his birthday was any other day I don't think I would feel so bad. Bonfire Night, hardly a day you forget. I don't know if its because I have never had a birthday card off my real family or what but its the little things that hurt the most.
Have I built up a fantasy of what having a real family means, yes I know its only a card. Is it supposed to hurt like this.