A Writer is Born?

I want to write.  I want people to read what I've written and get an enjoyment from it.  I want them to laugh, cry, and feel along with my characters.  I don't care about making money or being famous.  I would like to have an audience for what I write though.  I love to read, and I just want to give other people the same pleasure I feel when I read.  The problem is this... where to begin?  What do I write about?  How do I start?  I believe that I'm a fairly good writer.  I've written a Harry Potter fanfiction, and while it probably wasn't award winning, I think it was fairly good.  (if you want to read it, it's here http://www.fanfiction.net/s/2400733/1/)  But how do I come up with ideas of my own?  That's the problem.  If someone else gives me a plot, then I can do a fairly good job of making a story out of it, but just to sit down and write?  I get lost in thinking about how to start.  In Sister Act 2, Whoopi Goldberg's character says something to a young girl.  It goes something like this.  If you get up in the morning and all you can think about is singing, then you're supposed to be a singer.  I'm sure the same applies to writing.  When I get up in the morning... I think about more sleep.  Guess I'm supposed to be a sleeper.  So is a writer born?  Or is a writer made?  Should I sit down at my computer and stare at it until I come up with something?  Or should I give up and find some other way to channel my creativity?