Why do they have to grow up?

Okay, I am among the guilty who wish my kids would grow up to fast sometimes, but then there are days like today when I want my babies back. My oldest went to the lake with her friends this weekend, she called me when she got down there and all was right. No call yesterday and I can't get a hold of her today, she has that cell phone I am paying for turned off (a post for another day). I know she is okay, I like the kids she is with, I trust the parents who are along, but I hate not knowing what is going on in her life. I used to know every move she made, now there are a lot of times I feel like an outsider looking in. Yes I know the fact that she is growing up into a mature responsible person is good, but like I said there are days I want my baby back