I didn't know that was an option...

I was reading The Art of Parenting Twins last night (more book reviews coming soon) when I came across the following:

In some families I know, the parents don't tell their children they are twins. Although these children generally figure it out when they get to school and learn that not everybody has the same birthday, they may feel that their parents haven't leveld with them or prepared them for all the questions and interest.

It had never occurred to me that you could avoid telling twins that they were, well, twins.  In fact, I'm not quite sure how you would do that.  Avoid introducing the word "twin" to their vocabulary?  I really can't imagine doing that, but maybe I'm just not seeing the big picture here.