Hehe, Charlie was there when you were born, Al. He was sooo little, but yes, I imagine they stayed in contact. Charlie always changed foster parents after his birthday, so I like to think that the parents who got really attached to him might've tried to make a big celebration so it would seem fun, instead of awful, to have to pack up like that. Probably would've meant X-family from all over got together?
And yeah, I don't imagine he'd have overly much backstory with the other characters, but he knows who they all are and what they do - except Robert - at least, so there's something to grow on. :D