Last Day

How in the world can tomorrow be the last day of school??  I'm sure the kids would disagree, but this year has flown by.  Everett is a half-day away from being a first grader!  I can't even discuss the fact that Amelia is going into fourth grade....and I really don't want to discuss what kind of things fourth graders get into these days.  Is it completely unethical for a dad to hold his kids back a year in school if they are successful by all measures?  What about two years?  Now, that is worth discussing.