Empty nester ~ What to do?

When my kids were little and I was working and raising my family, the thought of not knowing what to do with my time was a concept that I couldn't quite wrap my head around.  Here I am though, all my kids on their own and more time than I know what to do with.  I tried 'retiring' for four months and it was definitely not for me.  Back to work I went and that has been good for me.  I think for a lot of women, raising your children and looking after their day to day needs becomes your identity, much like a man's job becomes his.  So, I have found this transition much harder than I thought.  I am 9 months child free (you don't ever stop worrying though) and still haven't found my new stride.  Now that I have fairly successfully raised my children into adults, what do I strive for next?  What do I want to accomplish with the time I have left in this life?  I don't know yet, everyday I ask myself.  When I figure it out, I'll let you know :)