Where has the time gone?

It literally seems like yesterday that I just had this little boy?  I have no clue where the time has gone but he's growing up right before my eyes.  He has been so excited to start "real" pre-school that he could hardly contain himself.  I dropped him off to his first day about 2 hours ago now.   I've been excited for him but sad that he's growing so fast. Last year he was able to go to some pre-preschool sessions with friends or at the community center.  It is finally sinking in now that I don't get to go with him anymore. He starts kindergarten next year.  Crazy!
Thirty more minutes and I get to go get him.  I'm looking forward to finding out how his day went.  Mine morning had been pretty boring without him here.  Man, I love that boy!