Growing up way too fast

Last night Connor slept in his big-boy bed for the first time!  We've had it set up now for about a week in his room along with his crib, but really wasn't planning on transitioning him to it until after his birthday which is less than 2 weeks away.  I just can't believe how fast he's growing up!  I think it's harder for me to see him out of his crib than it is for Connor.  I've loved every new stage that he's moved into and haven't had the emotional issues that come with each new stage...until now!  Don't get me wrong I'm grateful it's been an easy transition for him, but wow this stage feels like he's less of my baby and more a little boy.  I can only imagine what kindergarten is going to feel like! Yikes!