Time is cruising by

I sometimes feel like time is passing me by.
I don't feel like I've done the things I should have with my life.
Not that I'm depressed or unhappy quite the contrary.  I like my life the way it is.  Except I have these thoughts that if I look back in ten or twenty years I'll have regrets that I didn't work harder to get published or have some sort of career.
But I don't want to work just to be working.  I want to do something I love because why spend your whole life doing something you don't enjoy.  
My DD#1 turned 5 on Wednesday and I was looking at her baby pictures feeling a little melancholy for lack of a better word.   She's such a big girl now and I really am glad that baby stage is over.  But it makes me sad to think that in 5 years she'll need me less and then in ten years she'll be a temperamental teenager and then she'll will leave me.  I read somewhere once that kids get so they annoy the heck out of you so that when it is time for them to spread their wings and fly you're more than ready to give them the boot out of the nest.  Because if you had to let them go as babies or small children it would rip your heart out. 
So the progression of time has a purpose.