Leaving the Little

She has learned how to make her "Ls."
No more "Wucy."  Now it's a crystal clear "Lucy."
She'll be three in less than two weeks.
We don't travel with the pak-n-play or potty seat or booster seat for the table anymore.
I smile at her when I tell her she's such a big girl now but inside, a little part of me aches a bit for the little that is quickly being left behind.
Don't get me wrong.  Every age has been good and brings new pleasantries.  It's a joy to watch our children grow up.
But I miss the little.
I'm wondering if I always will.  There's something a little unsettling to me about leaving the baby/toddler stage behind for good.
Thankfulness settles in, though, and I am grateful for each of my babies though they may not be babies anymore.  I'm too aware that our time with them at home is short. 
So, my prayer is that we can be faithful to love them well and teach them what's really important (like the Gospel) and not get so worked up about the rest (like a messy house). 
Someone tell me, is that what everyone means when they say, "Enjoy your children.  It goes by too fast."?