I think that the whole presents thing would be a good incentive to remember birthdays. LOL. DS has always been like that with his memory. It's amazing. He remembers the date that we went on vacation last year, etc. It's his thing. I on the other hand can watch a movie and probably not remember it a week later. I constantly read books and can't remember the name of them. It's amazing on a different level.

LOL. Same here. DS7 remembers any date or number you put in front of him. I, on the other hand, still don't remember my own cell phone number

DS5 doesn't share DS7 number obsession.
Good luck at school with all the math knowledge your son already has. His math abilities remind me of DS7 when he was 5.