Grandparents and grandkids get along so well because they have a common enemy - the parents. Do you think this is true?

I do not think that either the children or the grandparents consider the parents enemies. It is more likely that children see only their parents in what seems like a punitive role because they are the ones who must say 'no.' Grandparents can be selective in their roles, and choose mostly positive ones, leaving the reprimanding to the parents. That's one of the best parts in being a senior grandparent.

I agree with patsy. 'Enemy' might not be the term. It's just that the parents are the ones who have the 'disciplinarian' image while the grandparents have the tendency to spoil or easily succumb to the kids' wishes.