Where's the inspiration?

So I'm thinking about myself and writing.  I have wanted to write ... felt a natural pull toward writing ... since I was a teen.  I am well beyond those years now, and I'm thinking... I remember I used to have all this PASSION about things.  Where did it go?  It's like I don't have enough interest in things these days to bother wanting to put the effort into shaping words about them. I have no sense of excitement about anything anymore.  Am I getting old?  Am I getting jaded?  I wrote one of the best stories of my life when I was screaming angry.  That emotion made its way into the story, and gave it a particular punch.  It's probably not very healthy to ALWAYS be experiencing extremes of passion--but there should be occasional rises of something, no?  Else everything would be just ... colorless.

So.  I'm looking for my lost passion.  It must be around here somewhere.  Did it get scared and go hide behind some pile of daily debris?  Or did it get discouraged with me and  think I didn't want or need it anymore... because I had too many other mundane things grabbing at my attention?  Did it give up on me? 

How do you rediscover a passion that once lived deep inside you, but seems to have vanished?