One thing I have been encountering is that more that one of my colleagues is dealing with parents who think that their child is "too smart" for kindergarten, or "already knows everything." I have had a few of these in the past, so my eyes automatically roll when I hear about it.
I wish I could be very blunt with each of these parents, or have enough expendable income to do my own public service announcement. It would go something like this:
Dear parent of the smartest child in the world,
Just because your child can read every word in the dictionary, count to infinity and beyond, speak two or more languages fluently, and identify every color that ever existed like charmeuse and aquamarine, does not mean they are ready for first grade. I know these children. I love these children. But these children have a hard time telling me what day tomorrow is, or telling me about a book they just read, or sharing their toys with their classmates. These kids have lots of facts and information in their smart little heads but they have no idea how to use it. Please allow their kindergarten teacher to help them learn how to use their smart brains.