Why Do I Keep Having These Dreams?

I am on summer vacation, and I have been having these dreams where school is still in session, but it is a non-working day. Just a day of fun. Like once it was just a no-work day, and then in another one it was--pajama day???? LOL. And at some point in the dream, I remember that I am supposed to be in summer vacation, but for some reason school just keeps going. Why am I having these dreams?