Growing up too fast!!

OK, I'm quickly realizing that my baby is not so much of a baby anymore. I've realized it several times over the last few weeks, but I'm still in denial. Tonight was a major milestone for us though. I've always either nursed William to sleep or once he was weaned, rocked him to sleep. We have our little night time routine and it's the same every night. We go in his room, he takes his Singulair, he turns off the light, I put him in his bed and kiss him, I sit in the rocking chair, we say his prayers and I sing "You Are My Sunshine". Sometime in the prayer or song, William hands me his blanket and his Pooh and now his alligator, a few minutes (sometimes seconds) later he climbs out of his bed or reaches for me to come get him and we rock or "dance" while he falls asleep. Tonight all of that happened except he never got out of his bed and fell asleep all by himself.
I am both happy and extremely sad about this. I'm happy in the fact that I'm the only one he wants to put him to sleep if I'm around and if he can go to sleep on his own it would be good, especially on hectic nights. I'm sad in the fact that this means my baby is growing up and it's one step closer to independence. He's already an independent toddler who doesn't want Mommy as often as he used to. I'm really having to get used to this and I will be going back to school soon. I know this probably has a lot to do with my sadness because I won't have as much time with him as I do now - we're together generally all day every day 6 days a week. His birthday also has me realizing that my baby is not a baby anymore. He's now and official toddler and is growing up way too fast.
OK, enough Mommy rambling. I'm just getting very nostalgic as his birthday is approaching. I promise I'll post pics of his party soon, I've just been quite busy and uploading pics have been the last thing on my mind.