Just be honest. Seriously, if other people have a problem with the idea...well, it's their problem and not yours. Think of this as a way to distinguish the cool people from the ones who aren't so cool.
My DD4 is thrilled that she's going to 1st grade next year and DS9 is pretty excited about starting middle school. To be honest, she might have been equally thrilled to be starting kindergarten, though I think she does have some idea that she's skipping kindergarten.
<sigh> If schools were reasonable about subject- and grade-accelerations for all kids who were able for them, mixed age classrooms would be the norm and we wouldn't have these problems!
Val
